System and method for fracture replacement of comminuted bone fractures or portions thereof adjacent bone joints

ABSTRACT

A system and method facilitating replacement of comminuted bone fractures or portions thereof adjacent bone joints. The system and method employs a prosthesis to replace at least a portion of the comminuted bone fractures. The prosthesis serves in reproducing the articular surface of the portion or portions of the comminuted bone fractures that are replaced. In doing so, the prosthesis serves in restoring joint viability and corresponding articulation thereof.

The present application claims the benefit of Provisional ApplicationNo. 61/552,387, filed Oct. 27, 2011, the contents of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is generally related to a medical device andmethod for use thereof for facilitating replacement of comminuted bonefractures. In particular, the present invention is related to a systemand method for use thereof to aid in the replacement of comminuted bonefractures adjacent bone joints to restore joint viability. Morespecifically, the present invention relates to a system and method foruse thereof for replacing comminuted bone fractures adjacent joints byproviding a prosthesis to replace the fractured bone or portions of thefractured bone to facilitate restoration of movement associated with thebone joint.

2. Description of the Prior Art

Comminuted bone fractures adjacent joints oftentimes result insignificant fragmentation of the bone. In fact, these types of bonefractures can often result in portions of the bone being severelyfragmented. That is, the number of fragments created by these types ofbone factures pose difficulties in repairing the bone. Bone plates haveoftentimes been used to aid repair of the comminuted bone fractures.However, even with use of bone plates, the comminuted bone fractures maynot be adequately reconstructed. For example, if severely fragmented,the proximal end portions of a humerus, the distal end portions of aradius, or the distal end portions of an ulna may not bereconstructible. As such, there is a need for a prosthesis affordingreplacement of the comminuted bone fractures or portions thereof torestore joint viability. The prosthesis can be used when the comminutedbone fractures need substantial support to aid repair or areirretrievably fragmented. Such a prosthesis can be used in replicatingarticular surfaces of the fractured bone to restore movement associatedwith a corresponding bone joint. For example, such a prosthesis can beconfigured to repair the proximal end portion of the humerus, the distalend portion of the radius, and the distal end portion of the ulna.

SUMMARY OF THE INVENTION

The present invention in one preferred embodiment contemplates a systemfor replacement of at least a portion of a comminuted humeral head, thesystem including a prosthesis and a bone plate, the prosthesis having anexterior surface being sized and shaped to approximate the surface ofthe at least a portion of the comminuted humeral head, the bone plateincluding a first surface, an opposite second surface, and at least onepost formed thereon, the first surface being adapted to contact at leasta portion of a humerus, the at least one post extending outwardly fromthe first surface, where one of the prosthesis and the at least one postincludes a male component, and the other of the prosthesis and the atleast one post includes a female component, the male and femalecomponents engaging one another to connect the prosthesis and the boneplate to one another.

In another preferred embodiment, the present invention contemplates asystem for replacement of at least a portion of a comminuted humeralhead, the system including a prosthesis having an exterior surface andat least one aperture provided therein, the exterior surface being sizedand shaped to approximate the surface of the at least a portion of thecomminuted humeral head; and a bone plate including a first surface, anopposite second surface, and at least one post formed thereon, the firstsurface being adapted to contact at least a portion of a humerus, the atleast one post extending outwardly from the first surface, where, whenthe system is positioned with respect to the humerus, the at least onepost extends through the humerus and engages the at least one apertureformed in the prosthesis to connect the prosthesis and the bone plate toone another.

In yet another preferred embodiment, the present invention contemplatesa system for replacement of at least a portion of a comminuted humeralhead, the system including a prosthesis having an exterior surface andat least one aperture formed therein, the exterior surface being sizedand shaped to approximate the surface of the at least a portion of thecomminuted humeral head; a first plate including a first surface and anopposite second surface, the first surface adapted to contact anexterior portion of a humerus; a second plate including a first surfaceand an opposite second surface, the first surface including at least onepost extending outwardly therefrom, and the second surface being adaptedto contact an interior portion of the humerus; and at least one fasteneradapted to attach the first and second plates to one another and thehumerus, where, when the system is position with respect to the humerus,the first plate and the second plate are attached to one another and thehumerus with the at least one fastener, and the at least one postextends through the humerus and engages the at least one aperture formedin the prosthesis to connect the prosthesis and the second plate to oneanother.

In still another preferred embodiment, the present inventioncontemplates a system for replacement of at least a portion of a carpalarticular surface of a radius, the system including a prosthesis havingan exterior surface and at least one aperture provided therein, theexterior surface being sized and shaped to approximate the surface ofthe at least a portion of the carpal articular surface of the radius,and the at least one aperture of the prosthesis being adapted to receiveat least one fastener therein; a bone plate including at least oneopening formed therein, at least a portion of the bone plate beingconfigured to be attached to the radius above the distal end thereof,the at least one opening of the bone plate being configured to receivethe at least one fastener therethrough; and the at least one fastenerhaving a first end for insertion through the at least one opening andinto the at least one aperture, the at least one fastener beingconfigured to secure attachment of the prosthesis and the bone plate toone another across a portion of a humerus.

In yet still another preferred embodiment, the present inventioncontemplates a system for replacement of at least a portion of a head ofan ulna, the system including a prosthesis having an exterior surface,an interior cavity, and at least one aperture provided therein, theexterior surface being sized and shaped to approximate the surface ofthe at least a portion of the head of the ulna, the interior cavityconfigured to receive at least one of bone fragments of the ulna and asubstrate therein, and the at least one aperture of the prosthesisconfigured to receive at least one fastener therein; a bone plateincluding at least one opening formed therein, at least a portion of thebone plate being configured to be attached to the ulna above the distalend thereof, the at least one opening of the bone plate being configuredto receive the at least one fastener therethrough; and the at least onefastener having a first end for insertion through the at least oneopening and into the at least one aperture, the at least one fastenerbeing configured to secure attachment of the prosthesis and the boneplate to one another across a portion of a humerus.

It is understood that both the foregoing general description and thefollowing detailed description are exemplary and explanatory only, andare not restrictive of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate preferred embodiments of theinvention. Together with the description, they serve to explain theobjects, advantages and principles of the invention. In the drawings:

FIG. 1 depicts a partial cross-sectional elevational view of a firstillustrative embodiment of a humeral head replacement system including ahead portion and a bone plate portion attached to one another and ahumerus using fasteners;

FIG. 2 depicts a partial cross-sectional elevational view of a secondillustrative embodiment of the humeral head replacement system includinga head portion and a bone plate portion attached to one another and ahumerus using fasteners;

FIG. 3 depicts a partial cross-sectional perspective view of the headportion depicted in FIG. 2;

FIG. 4 depicts a partial cross-sectional elevational view of a thirdillustrative embodiment of the humeral head replacement system includinga head portion and a bone plate portion attached to one another and ahumerus using fasteners;

FIG. 5 depicts a partial cross-sectional elevational view of a fourthillustrative embodiment of the humeral head replacement system includinga head portion and a bone plate portion attached to one another and ahumerus using fasteners;

FIG. 6 depicts a partial cross-sectional elevational view of a fifthillustrative embodiment of the humeral head replacement system includinga head portion and a bone plate portion attached to one another and ahumerus using fasteners;

FIG. 6A depicts a partial cross-sectional fragmentary view of the headportion of the fifth illustrative embodiment of the humeral headreplacement system with an alternate engagement mechanism between thehead portion and the fasteners;

FIG. 7 depicts a perspective exploded-parts view of a sixth illustrativeembodiment of the humeral head replacement system including a headportion and a bone plate portion attachable to one another using anoversized fastener;

FIG. 8 depicts a partial cross-sectional elevational view of a seventhillustrative embodiment of the humeral head replacement system includinga head portion and a bone plate portion attached to one another and ahumerus using a post formed integrally with the bone plate portion;

FIG. 9 depicts a partial cross-sectional elevational view of an eighthillustrative embodiment of the humeral head replacement system includinga head portion and a bone plate portion attached to one another and ahumerus using a post formed integrally with the bone plate portion and aprojection formed integrally with the head portion;

FIG. 10 depicts a partial cross-sectional elevational view of a ninthillustrative embodiment of the humeral head replacement system includinga head portion, a bone plate portion, and an intermediate portion, thebone plate portion and the intermediate portion being attached to oneanother and a humerus using fasteners, and the intermediate portionbeing attached to the head portion using a post formed integrally withthe intermediate portion;

FIG. 10A depicts the intermediate plate portion of FIG. 10 including anangled post formed integrally therewith;

FIG. 11 depicts a perspective view of another configuration of anintermediate plate portion for use in the humeral head replacementsystem of FIG. 10;

FIG. 12 depicts a perspective view of yet another configuration of anintermediate plate portion for use in the humeral head replacementsystem of FIG. 10;

FIG. 13 depicts a partial cross-sectional elevational view of analternate configuration of a head portion and an intermediate plateportion for use in the humeral head replacement system of FIG. 10 withan alternate engagement mechanism between the head portion and theintermediate portion;

FIG. 14 depicts a partial cross-sectional elevational view of a tenthillustrative embodiment of the humeral head replacement system includinga head portion, a bone plate portion, and a base plate portion, the boneplate portion and the base plate portion being attached to one anotherand a humerus using fasteners, and the base plate portion being attachedto the head portion using a post formed integrally with the base plateportion;

FIG. 15 depicts a perspective exploded-parts view the head portion andthe base plate portion depicted in FIG. 14;

FIG. 16 depicts a perspective view of another configuration of a baseplate portion for use in the humeral head replacement system of FIG. 14;

FIG. 17 depicts a perspective view of yet another configuration of abase plate portion for use in the humeral head replacement system ofFIG. 14;

FIG. 18 depicts a perspective exploded-parts view of otherconfigurations of a head portion and a base plate portion for use in thehumeral head replacement system of FIG. 14;

FIG. 19 depicts an elevational view of still other configurations of ahead portion and a base plate portion for use in the humeral headreplacement system of FIG. 14;

FIG. 20 depicts a perspective view of the base plate portion depicted inFIG. 19;

FIG. 21 depicts a perspective exploded-parts view of an illustrativeembodiment of a distal radius replacement system including a distalradius replacement portion and a bone plate portion;

FIG. 22 depicts an elevational view of the distal radius systemreplacement system positioned with respect to a radius, the distalradius replacement portion and the bone plate portion being attached toone another and to the radius using fasteners, and the distal radiusreplacement portion being depicted partially in phantom; and

FIG. 23 depicts a perspective view of an illustrative embodiment of adistal ulna replacement system including a prosthetic portion and a boneplate portion attached to one another and to an ulna using fasteners,the ulna being depicted in phantom.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The systems for facilitating replacement of comminuted bone fractures orportions thereof and the methods for use thereof are depicted in theaccompanying drawings. The systems of the present invention provide aprosthesis affording replacement of the comminuted bone fractures orportions thereof adjacent joints to facilitate restoration of jointviability. While the below-described systems are used in associationwith the proximal end portion of a humerus, the distal end portion of aradius, and a distal end portion of an ulna, the present invention isnot limited thereto. That is, the systems and methods of the presentinvention can be configured for use elsewhere in the human body.

Systems of the present invention can be used in replacing a fracturedhumeral head or portions thereof at the proximal end of a humerus H thathave been irretrievably fragmented. These systems are humeral headreplacement systems, and various illustrative embodiments thereof aredepicted in FIGS. 1-20 and are assigned numerals 20, 80, 140, 200, 260,340, 380, 440, 510, and 600. Where possible, the components and featuresof the various embodiments of can be combined and used with one another.A humeral head replacement system is also disclosed in U.S. Ser. No.13/282,810, the contents which is incorporated herein by reference.

Systems of the present invention can also be used in replacing at leastportions of a fractured distal end of a radius and at least portions ofa fractured distal end of an ulna. These systems are referred to as adistal radius replacement system 700 (depicted in FIGS. 21 and 22) and adistal ulna replacement system 800 (depicted in FIG. 23). A distalradius replacement system is also disclosed in U.S. Ser. No. 13/663,129by the same inventor, being filed concurrently herewith, the contents ofwhich is incorporated herein by reference.

Humeral head replacement systems 20, 80, 140, 200, 260, 340, 380, 440,510, and 600, distal radius replacement system 700, and distal ulnareplacement system 800 are constructed of surgical grade materialssuitable for human implantation. As such, metal (such as titanium) orother artificial materials can be used for constructing thebelow-discussed components of humeral head replacement systems 20, 80,140, 200, 260, 340, 380, 440, 510, and 600, distal radius replacementsystem 700, and distal ulna replacement system 800.

First humeral head replacement system 20 is depicted in FIG. 1 inposition with respect to a humerus H. Humeral head replacement system 20includes a head or prosthetic portion 22 and a bone plate portion 24.Head portion 22 serves as a prosthesis for replacement of the humeralhead or portions thereof, and bone plate portion 24 is attached tohumerus H to provide a rigid structure for attaching head portion 22thereto. The rigid structure provided by the attachment of bone plateportion 24 to humerus H allows head portion 22 to be secured in positionon humerus H.

As depicted in FIG. 1, bone plate portion 24 is attached to humerus H,and includes a first portion 26 and a second portion 28. As discussedbelow, first portion 26 is used in attaching bone plate portion 24 tohumerus H at or adjacent a surgical neck SN, and second portion 28 isused in attaching bone plate portion 24 to at least one of a greatertubercle and a lesser tubercle (each generally referred to by the bycharacter T) in the figures. Bone plate portion 24 includes a length anda longitudinal axis extending between a first end 30 and a second end32. Furthermore, the width (i.e., the dimensions perpendicular to thelength) of bone plate portion 24 can vary along the length thereof tofacilitate contact with different portions of humerus H. For example,second portion 28 can be wider than first portion 26 to accommodatecontact thereof with both greater and lesser tubercles T. Anillustrative shape for the perimeter of bone plate portion 24 can beseen in FIG. 7.

Bone plate portion 24 includes both an upper surface 34 and a lowersurface 36 extending along first and second portions 26 and 28. Lowersurface 36 can be contoured to contact different portions of humerus H.That is, lower surface 36 can be shaped in accordance with portions ofhumerus H with which it is to be contacted. For example, lower surface36 at first portion 28 can be contoured to contact humerus H at and/oradjacent surgical neck SN, and lower surface 36 at second portion 28 canbe contoured to contact humerus H at and/or adjacent portions of greatertubercle and/or lesser tubercle T.

First portion 26 of bone plate portion 24 is configured to receive oneor more fasteners (such as bone screws 40) therethrough to facilitateattachment thereof at or adjacent surgical neck SN. To that end, firstportion 26 of bone plate portion 24 can include various apertures 42(extending between upper and lower surfaces 30 and 32) for receivingbone screws 40. Bone screws 40 can be configured to facilitateengagement with bone plate portion 24 and humerus H. For example, bonescrews 40 can each include a shaft 44 and a head 46 that are boththreaded. Threaded shafts 44 can serve in facilitating engagement withapertures 48 formed in humerus H, and threaded heads 46 can serve infacilitating engagement with first plate portion 24 via complimentarythreads (not shown) provided in apertures 36. When lower surface 36 (atfirst portion 26) is properly positioned with respect to humerus H, bonescrews 40 can be inserted into apertures 42 and into humerus H to securebone plate portion 24 to humerus H. Furthermore, apertures 42 can becountersunk to receive threaded heads 46, so that at least portions ofthreaded heads 46 ultimately can lie below upper surface 34.

Second portion 28 of bone plate portion 24 is configured to receive oneor more fasteners 50 therethrough to facilitate attachment of headportion 22, bone plate portion 24, and humerus H to one another. To thatend, second portion 28 can include one or more apertures 52 therethrough(extending between upper and lower surfaces 34 and 36) for receivingfasteners 50. Fasteners 50 can each include a shaft 54 and a head 56.Shafts 54 can serve in facilitating engagement with head portion 22 andhumerus H, and heads 56 can serve in facilitating engagement with secondportion 28. As discussed below, when lower surface 36 (at second portion28) is properly positioned with respect to humerus H, fasteners 50 canbe inserted into apertures 52, into apertures 60 formed in humerus H,and into apertures 62 formed in head portion 22. Furthermore, apertures52 can be countersunk to receive heads 56, so that at least portions ofheads 56 ultimately can lie below upper surface 34.

Four fasteners 50 and four apertures 52 are depicted in FIG. 1 arrangedin alignment with one another along the longitudinal axis of bone plateportion 24. However, the number, arrangement, and spacing of apertures52 (and hence, corresponding fasteners 50) can vary. For example, ifsecond portion 28 is sized to contact both greater and lesser tuberclesT, second portion 28 would be larger than if sized to contact only oneof greater and lesser tubercles T. Thus, a larger number of apertures 52(and corresponding fasteners 50) can be used, and apertures 52 (andcorresponding fasteners 50) can be spaced farther apart from oneanother. Furthermore, depending on the size of second portion 28,apertures 52 (and corresponding fasteners 50) can be arranged alongand/or on either side the longitudinal axis of bone plate portion 24,and, for example, can be arranged in triangular, rectangular, anddiamond-shaped patterns.

The apertures 52 can be oriented to facilitate various orientations offasteners 50 with respect to one another in three dimensions. Asdepicted in FIG. 1, for example, apertures 52 are oriented such thatthree of fasteners 50 are parallelly oriented with respect to oneanother, and one of fasteners 50 obliquely oriented with respect to theother three fasteners 50. Alternatively, apertures 52 can be oriented sothat two or more of fasteners 50 are parallelly oriented with respect toone another, and/or be oriented so that two or more of fasteners 50 areobliquely oriented with respect to one another. To illustrate, apertures52 can allow each of fasteners 50 to be parallelly oriented relative toone another, or can allow each of fasteners 50 to be obliquely orientedrelative to one another. The parallel and oblique orientations can beinto and out of the page defined by FIG. 1.

Shafts 54 and heads 56 of fasteners 50 (and the shafts and heads ofsimilar fasteners discussed below) can have different sizes and shapes(e.g., be configured to have cylindrical or frusto-conical shapedportions), and have regular roughened or rough surfaces (hereinafterregular roughened surfaces), irregular roughened or rough surfaces(hereinafter irregular roughened surfaces), and/or smoothened or smoothsurfaces (hereinafter smoothened surfaces) provided on the cylindricalor frusto-conical shaped portions. The regular roughened surfaces arerepeating patterns of surface protrusions or indentations (such asthreads, ratchets, or similar structures), and the irregular roughenedsurfaces (such as barbs or similar structures) are non-repeating surfaceprotrusions or indentations. The regular roughened surfaces, theirregular roughened surfaces, and/or the smoothened surfaces can servein preventing withdrawal of fasteners 50 from the components of humeralhead replacement system 20 and humerus H.

To illustrate, regular roughened surfaces provided on shafts 54 can beused for complimentary engagement or interference, press, or frictionfits with the components of humeral head replacement system 20 orportions of humerus H to which shafts 54 are contacted to preventwithdrawal therefrom. If complimentary engagement surfaces are providedin the components or humerus H, regular roughened surfaces of shafts 54can complimentarily interface with the complimentary engagementsurfaces. For example, threads/ratchets formed on shafts 54 can engagecorresponding threads/ratchets provided in apertures formed in thecomponents to which shafts 54 are engaged to prevent withdrawal offasteners 50. If no complimentary engagement surfaces are provided inthe components or humerus H, the regular roughened surfaces can be usedin deforming the components or humerus H to provide an interference,press, or friction fit therebetween. For example, ratchets formed onshafts 54 can engage, and, in doing so, deform apertures formed in thebone of humerus H to prevent withdrawn of fasteners 50.

In addition, to illustrate, irregular roughened surfaces provided onshafts 54 can be used in deforming the components of humeral headreplacement system 20 and humerus H to provide an interference, press,and/or friction fit therebetween. For example, barbs formed on shafts 54can engage, and, in doing so, deform apertures formed in the bone ofhumerus H. The contact of the barbs within these apertures in thehumerus H afforded by such deformation would serve in preventingwithdrawal of fasteners 50 therefrom.

Additionally, to illustrate, smoothened surfaces provided on shafts 54can be used in deforming the components of the humeral head replacementsystem 20 and humerus H to provide an interference, press, and/orfriction fit therebetween. For example, smoothened surfaces (such astapered or conical surfaces) formed on shafts 54 can engage and deformapertures formed in the components. The compression and friction forcesapplied to the smoothened surfaces within the apertures would serve inpreventing withdrawal of fasteners 50 therefrom.

Like threaded heads 46 (of bone screws 40), heads 56 can, as discussedabove, be threaded to serve in facilitating engagement withcomplimentary threads (not shown) provided in apertures 52. Furthermore,shafts 54 can each include a first portion 54A and a second portion 54B.First portions 54A can be used in engaging apertures 60 formed throughhumerus H, and second portions 54B can be used in engaging correspondingsurfaces of apertures 62 formed in head portion 22. First and secondportions 54A and 54B can be configured to have identical or differentshapes, lengths, and widths, and can include the above-discussed regularroughened surfaces, irregular roughened surfaces, and/or smoothenedsurfaces.

The connection between head portion 22 and bone plate portion 24afforded by fasteners 50 serves in maintaining the positions of thecomponents of humeral head replacement system 20 relative to humerus H.However, the configuration of fasteners 50 can also serve in maintainingthe position of humeral head replacement system 20 relative to humerusH. The regular or irregular roughened surfaces can serve in fixingfasteners 50 relative to humerus H. For example, if first portions 54Ainclude threads/ratchets 66, threads/ratchets 66 of first portions 54Awould engage apertures 60 to resist linear rearward movement (or backingout) of fasteners 50 from humerus H.

Head portion 22, as depicted in FIG. 1, is generally shaped as asubstantially solid spherical cap. Head portion 22 includes an articularsurface 70 and a bone-contacting surface 72. Articular surface 70 issubstantially similar to the shape of the articular surface of thehumeral head (or portions thereof) for which it is used in replacing.Furthermore, bone-contacting surface 72 contacts humerus H along surfaceS₁ and apertures 62 (for receiving second portions 54B) extend throughbone-contacting surface 72 into head portion 22. As depicted in FIG. 1,bone-contacting surface 72 is substantially flat. However,bone-contacting surface 72 can be concave, convex, or undulating withvarious concavities and convexities to accommodate the shape of surfaceS₁. Surface S₁ can be prepared to interface with the shape ofbone-contacting surface 72.

Depending, as discussed above, on whether second portions 54B haveregular roughened surfaces, irregular roughened surfaces, and/orsmoothened surfaces, engagement of fasteners 50 to head portion 22 wouldbe different. For example, if second portions 54B includethreads/ratchets 68, second portions 54B can engage (via complimentarystructures formed in and/or via interference, press, and/or frictionfits with) apertures 62. Furthermore, if second portions 54B havesmoothened surfaces, second portions 54B can engage (via interference,press, and/or friction fits) surfaces formed in apertures 62 Theseinteractions serve in attaching fasteners 50 (and hence, bone plateportion 24) to head portion 22.

If threads/ratchets are used for attachment, configurations ofthreads/ratchets 66 and 68 of first and second portions 54A and 54B,respectively, can be different to accommodate their respective uses. Forexample, first portion 54A can have coarser threads for engagement withhumerus H, and second portion 54B can have finer threads for engagementto head portion 22. Furthermore, first portion 54A can have largerratchets for engagement with humerus H, and second portion 54B can havesmaller ratchets for engagement with head portion 22.

Second humeral head replacement system 80 is depicted in FIG. 2 inposition with respect to humerus H. Humeral head replacement system 80includes a head or prosthetic portion 82 (also depicted in FIG. 3) and abone plate portion 84. Like head portion 22, head portion 82 serves as aprosthesis for replacement of humeral head or portions thereof, and,like bone plate portion 24, bone plate portion 84 is attached to humerusH to provide a rigid structure for attaching head portion 82 thereto.The rigid structure provided by the attachment of bone plate portion 84to humerus H allows head portion 82 to be secured in position on humerusH.

As depicted in FIG. 2, bone plate portion 84 is attached to humerus H,and includes a first portion 86 and a second portion 88. First portion86 is used in attaching bone plate portion 84 to humerus H at oradjacent surgical neck SN, and second portion 88 is used in attachingbone plate portion 84 to at least one of greater or lesser tubercles T.Bone plate portion 84 includes a length and a longitudinal axisextending between a first end 90 and a second end 92. Furthermore, likethe width of bone plate portion 24, the width (i.e., the dimensionsperpendicular to the length) of bone plate portion 84 can vary along thelength thereof to facilitate contact with different portions of humerusH. For example, second portion 88 can be wider than first portion 86 toaccommodate contact thereof with both of greater and lesser tubercles T.An illustrative shape for the perimeter of bone plate portion 84 can beseen in FIG. 7.

Like bone plate portion 24, bone plate portion 84 includes both an uppersurface 94 and a lower surface 96 extending along first and secondportions 86 and 88. Like lower surface 36 of first and second portions26 and 28, lower surface 96 of first and second portions 86 and 88 canbe contoured to contact different portions of humerus H.

Furthermore, although not depicted in FIG. 2, first portion 86 caninclude apertures (similar to apertures 42) extending between upper andlower surfaces 94 and 96 that are configured for receiving fastenerssuch as bone screws 40. Like first portion 26 of bone plate portion 24,first portion 86 of bone plate portion 84 can be attached at or adjacentsurgical neck SN using bone screws 40. Bone screws 40 can engage theapertures formed in first portion 86, as well as apertures (not shown)formed in humerus H.

Second portion 88 of bone plate portion 84 is configured to receive oneor more fasteners 100 therethrough to facilitate attachment of headportion 82, bone plate portion 84, and humerus H to one another. To thatend, second portion 88 can include one or more apertures 102therethrough (extending between upper and lower surfaces 94 and 96) forreceiving fasteners 100. Fasteners 100 can each include a shaft 104 anda head 106. Shafts 104 can serve in facilitating engagement with headportion 82 and humerus H, and heads 106 can serve in facilitatingengagement with second portion 88. When lower surface 96 (at secondportion 88) is properly positioned with respect to humerus H, fasteners100 can be inserted into apertures 102, into apertures 110 formed inhumerus H, and into apertures 112 formed in head portion 82.Furthermore, apertures 102 can be countersunk to receive heads 106, sothat at least portions of heads 106 ultimately can lie below uppersurface 94.

Three fasteners 100 and three apertures 102 are depicted in FIG. 2arranged to have a generally parallel orientation with respect to oneanother. Fasteners 100 and apertures 102 are spaced along thelongitudinal axis of bone plate portion 84. Furthermore, in similarfashion to apertures 52 (and corresponding fasteners 50) of firsthumeral head replacement system 20, the number, arrangement, spacing,and orientation of apertures 102 (and hence, corresponding fasteners100) can vary further. Like with first humeral head replacement system20, these variations (such as positioning thereof on either side of thelongitudinal axis and the pattern formed thereby) for apertures 102 (andcorresponding fasteners 100) can occur because second portion 88 issized to contact varying portions of humerus H, and the desire to havethe fasteners 100 parallelly or obliquely oriented with respect to oneanother.

Like shafts 54 and heads 56, shafts 104 and heads 106 can be configuredto have cylindrical or frusto-conical shaped portions, and have regularroughened surfaces, irregular roughened surfaces, and/or smoothenedsurfaces provided on the cylindrical or frusto-conical shaped portions.Furthermore, like shafts 54, shafts 104 can include first portions 104Aused in engaging apertures 110 formed through humerus H, and secondportions 104B used in engaging corresponding surfaces of apertures 112formed in head portion 82. First and second portions 104A and 104B canbe configured to have identical or different shapes, lengths, andwidths, and can include the above-discussed regular roughened surfaces,irregular roughened surfaces, and/or smoothened surfaces.

The connection between head portion 82 and bone plate portion 84afforded by fasteners 100 serves in maintaining the positions of thecomponents of humeral head replacement system 80 relative to humerus H.Indeed, portions of humerus H are clamped between head portion 82 andbone plate portion 84. Furthermore, in addition to the connectionbetween head portion 82 and bone plate portion 84 afforded thereby, theconfiguration of fasteners 100 can serve in resisting movement (andhence, maintaining the position) of the components of humeral headreplacement system 80 relative to humerus H. That is, the regular orirregular roughened surfaces formed on shafts 104 can serve in fixingfasteners 100 relative to humerus H. For example, if first portions 104Ainclude threads/ratchets 116, threads/ratchets 116 would resist linearrearward movement (or backing out) of fasteners 100 from apertures 110.

Head portion 82, as depicted in FIGS. 2 and 3, is generally shaped as asubstantially semi-hollow spherical cap. Head portion 82 includes anarticular surface 120, an interior surface 121, a bone-contacting rim122, an interior cavity 123 delineated at least in part by interiorsurface 121 and bone-contacting rim 122, and slats 124, 126, and 128.Articular surface 120 is substantially similar to the shape of thearticular surface of the humeral head (or portions thereof) for which itis used in replacing. Furthermore, the thickness of head portion 82between articular and interior surfaces 120 and 121, as well as thethicknesses of slats 124, 126, and 128, can vary.

As depicted in FIG. 2, bone-contacting rim 122 is formed at a base 130of head portion 82, and contacts surface S₂ of humerus H.Bone-contacting rim 122 can be configured to accommodate the shape ofsurface S₂, and surface S₂ can be prepared to interface with the shapeof bone-contacting rim 122. Furthermore, slats 124, 126, and 128 includeapertures 112 for receiving fasteners 100. Slats 124, 126, and 128extend between portions of interior surface 121 in interior cavity 123,and are positioned at intervals between base 130 and apex 132 of headportion 82. A substrate (not shown) can be positioned between slats 124,126, and 128 to reinforce head portion 82. For example, polymericmaterial such as, polyethylene can be provided in the space betweenslats 124, 126, and 128.

Apertures 112 formed in slats 124, 126, and 128 can be aligned with oneanother to facilitate receipt of fasteners 100. That is, each of slats124, 126, and 128 includes one of apertures 112 for receipt of acorresponding one of fasteners 100. Apertures 112 can be aligned toafford different orientations of fasteners 100 with respect to slats124, 126, and 128. For example, as depicted in FIGS. 2 and 3, apertures112 (corresponding to each of fasteners 100) are aligned so thatfasteners 100 are perpendicularly angled with respect to slats 124, 126,and 128. However, apertures 112 (corresponding to each of fasteners 100)can be aligned so that fasteners 100 are obliquely angled with respectto slats 124, 126, and 128. If the substrate is provided between slats124, 126, and 128, apertures 112 would also be extended through thesubstrate.

As depicted in FIGS. 2 and 3, slats 124, 126, and 128 decrease in sizefrom bone-contacting rim 122 to apex 132. Slats 124, 126, and 128depicted in FIGS. 2 and 3 also have generally parallel orientations withrespect to one another and are spaced equally apart from one another.However, slats 124, 126, and 128 can have angled orientations withrespect to one another, and can have concave surfaces and/or convexsurfaces, or include undulating surfaces with various concavities andconvexities. Furthermore, slat 124 can include a bone-contacting surface134 for engaging humerus H at surface S₃. Like bone-contacting surface72 of head portion 22, bone-contacting surface 134 can be concave,convex, or undulating with various concavities and convexities toaccommodate the shaped of surface S₃. Furthermore, surface S₃ can beprepared to interface with the shape of bone-contacting surface 134.

Depending on whether second portions 104B have regular roughenedsurfaces, irregular roughened surfaces, and/or smoothened surfaces,engagement of fasteners 100 to head portion 82 would be different. Forexample, if second portions 104B include threads/ratchets, secondportions 104B can engage (via complimentary structures formed in and/orvia interference, press, and/or friction fits with) apertures 112.Furthermore, if second portions 104B have smoothened surfaces 136,second portions 104B can engage (via interference, press, and/orfriction fits) surfaces formed in apertures 112. The interactionsafforded by the complimentary structures and interference, press, and/orfriction fits serve in attaching fasteners 100 to head portion 82 byresisting linear movement (or backing out) of fasteners 100 from headportion 82 after insertion into apertures 112.

Third humeral head replacement system 140 is depicted in FIG. 4 inposition with respect to humerus H. Humeral head replacement system 140includes a head or prosthetic portion 142 and a bone plate portion 144.Like head portion 22, head portion 142 serves as a prosthesis forreplacement of the humeral head or portions thereof, and, like boneplate portion 24, bone plate portion 144 is attached to humerus H toprovide a rigid structure for attaching head portion 142 thereto. Therigid structure provided by the attachment of bone plate portion 142 tohumerus H allows head portion 142 to be secured in position on humerusH.

As depicted in FIG. 4, bone plate portion 144 is attached to humerus H,and includes a first portion 146 and a second portion 148. First portion146 is used in attaching bone plate portion 144 to humerus H at oradjacent surgical neck SN, and second portion 148 is used in attachingbone plate portion 144 to at least one of greater or lesser tubercles T.Bone plate portion 144 includes a length and a longitudinal axisextending between a first end 150 and a second end 152. Furthermore,like the width of bone plate portion 24, the width (i.e., the dimensionsperpendicular to the length) of bone plate portion 144 can vary alongthe length thereof to facilitate contact with different portions ofhumerus H. For example, second portion 148 can be wider than firstportion 146 to accommodate contact thereof with both of greater andlesser tubercles T. An illustrative shape for the perimeter of boneplate portion 144 can be seen in FIG. 7.

Like bone plate portion 24, bone plate portion 144 includes both anupper surface 154 and a lower surface 156 extending along first andsecond portions 146 and 148.

Like lower surface 36 of first and second portions 26 and 28, lowersurface 156 of first and second portions 146 and 148 can be contoured tocontact different portions of humerus H.

Furthermore, although not depicted in FIG. 4, first portion 146 caninclude apertures (similar to apertures 42) extending between upper andlower surfaces 154 and 156 that are configured for receiving fastenerssuch as bone screws 40. Like first portion 26 of bone plate portion 24,first portion 146 of bone plate portion 144 can be attached at oradjacent surgical neck SN using bone screws 40. Bone screws 40 canengage the apertures formed in the first portion 146, as well asapertures (not shown) formed in humerus H.

Second portion 148 of bone plate portion 144 is configured to receiveone or more fasteners 160 therethrough to facilitate attachment of headportion 142, bone plate portion 144, and humerus H to one another. Tothat end, second portion 148 can include one or more apertures 162therethrough (extending between upper and lower surfaces 154 and 156)for receiving fasteners 160. Fasteners 160 can each include a shaft 164and a head 166. Shafts 164 can serve in facilitating engagement withhead portion 142 and humerus H, and heads 166 can serve in facilitatingengagement with second portion 148. When lower surface 156 (at secondportion 148) is properly positioned with respect to humerus H, fasteners160 can be inserted into apertures 162, into apertures 170 formed inhumerus H, and into apertures 172 formed in head portion 142.Furthermore, apertures 162 can be countersunk to receive heads 166, sothat at least portions of heads 166 ultimately can lie below uppersurface 154.

Three fasteners 160 and three apertures 162 are depicted in FIG. 4arranged to have a generally parallel orientation with respect to oneanother. Fasteners 160 and apertures 162 are spaced along thelongitudinal axis of bone plate portion 144. Furthermore, in similarfashion to apertures 52 (and corresponding fasteners 50) of firsthumeral head replacement system 20, the number, arrangement, spacing,and orientation of apertures 162 (and hence, corresponding fasteners160) can vary further. Like with first humeral head replacement system20, these variations (such as the positioning thereof on either side ofthe longitudinal axis and pattern formed thereby) for apertures 162 (andcorresponding fasteners 160) can occur because second portion 148 issized to contact varying portions of humerus H, and the desire to havethe fasteners 160 parallelly or obliquely oriented with respect to oneanother.

Like shafts 54 and heads 56, shafts 164 and heads 166 can be configuredto have cylindrical or frusta-conical shaped portions, and have regularroughened surfaces, irregular roughened surfaces, and/or smoothenedsurfaces provided on the cylindrical or frusto-conical shaped portions.Furthermore, like shafts 54, shafts 164 can include first portions 164Aused in engaging apertures 170 formed through humerus H, and secondportions 164B used in engaging corresponding surfaces of apertures 172formed in head portion 142. First and second portions 164A and 164B canbe configured to have identical or different shapes, lengths, andwidths, and can include the above-discussed regular roughened surfaces,irregular roughened surfaces, and/or smoothened surfaces.

The connection between head portion 142 and bone plate portion 144afforded by fasteners 160 serves in maintaining the positions of thecomponents of humeral head replacement system 140 relative to humerus H.Indeed, portions of humerus H are clamped between head portion 142 andbone plate portion 144. Furthermore, in addition to the connectionbetween head portion 142 and bone plate portion 144 afforded thereby,the configuration of fasteners 160 can serve in resisting movement (andhence, maintaining the position) of the components of humeral headreplacement system 140 relative to humerus H. That is, the regular orirregular roughened surfaces formed on shafts 164 can serve in fixingfasteners 160 relative to humerus H. For example, if first portions 164Ainclude threads/ratchets 176, threads/ratchets 176 would resist linearrearward movement (or backing out) of fasteners 160 from apertures 170.

Head portion 142, as depicted in FIG. 4, is generally shaped as asubstantially semi-hollow spherical cap. Head portion 142 includes anarticular surface 180, an interior surface 181, a bone-contacting rim182, an interior cavity 183 delineated at least in part by interiorsurface 181 and bone-contacting rim 182, and a substrate 184 provided ininterior cavity 183. Articular surface 180 is substantially similar tothe shape of the articular surface of the humeral head (or portionsthereof) for which it is used in replacing. The thickness of headportion 142 between articular and interior surfaces 180 and 181 canvary. As depicted in FIG. 4, bone-contacting rim 182 is formed at a base190 of head portion 142, and contacts surface S₄ of humerus H.Bone-contacting rim 182 can be configured to accommodate the shape ofsurface S₄, and surface S₄ can be prepared to interface with the shapeof bone-contacting rim 182.

Substrate 184 can be formed from a material other than the material usedin forming the remainder of head portion 142. For example, as depictedin FIG. 4, substrate 184 can be lattice structure such as a regular orirregular wire mesh material. Substrate 184 can also be a solidpolymeric material such as, for example, polyethylene. Substrate 184 canbe attached, adhered, and/or fastened to interior surface 181, canextend from base 190 to apex 192 of head portion 142, and can be used toreinforce head portion 142. Furthermore, apertures 172 are formed insubstrate 184. Apertures 172 can be formed prior to receipt of fasteners160 therein, or can be formed by the force of penetration of fasteners160. Forming apertures 172 by the force of penetration significantlydiminishes the need for accurately targeting fasteners to engage thecomponents of humeral head replacement system 140. Furthermore,substrate 184 can include a bone-contacting surface 194 for engaginghumerus H at surface S₅. Like bone-contacting surface 72 of head portion22, bone-contacting surface 194 can be concave, convex, or undulatingwith various concavities and convexities to accommodate the shape ofsurface S₅. Furthermore, surface S₅ can be prepared to interface withthe shape of bone-contacting surface 194. If substrate 184 is a wiremesh material, surface S₅ can be prepared to facilitate growth of boneinto the wire mesh material.

Depending on whether apertures 172 are formed prior to receipt offasteners 160 or formed by the force of penetration of fasteners 160,and whether second portions 164B have regular roughened surfaces (suchas threads/ratchets 196 depicted in FIG. 4), irregular roughenedsurfaces, and/or smoothened surfaces, engagement of fasteners 160 tohead portion 142 would be different.

For example, if apertures 172 are formed prior to receipt of fasteners160, second portions 164B can include regular roughened surfaces (suchas threads/ratchets 196) used for engaging complimentary structuresformed in apertures 172 or engaging (via interference, press, and/orfriction fits) surfaces formed in apertures 172. Furthermore, ifapertures 172 are formed by the force of penetration of fasteners 172,second portions 164B can include regular roughened surfaces (such asthreads/ratchets 196) or irregular roughened surfaces—the regular andirregular roughened surfaces can be used to facilitate penetration offasteners 160 into and interference, press, and/or friction fits withsubstrate 184. The interactions afforded by the complimentary structuresand the interference, press, and/or friction fits serve in attachingfasteners 160 to head portion 142 by resisting linear movement (orbacking out) of fasteners 160 from head portion 142 after insertion intoapertures 112.

Fourth humeral head replacement system 200 is depicted in FIG. 5 inposition with respect to humerus H. Humeral head replacement system 200includes a head or prosthetic portion 202 and a bone plate portion 204.Like head portion 22, head portion 202 serves as a prosthesis forreplacement of the humeral head or portions thereof, and, like boneplate portion 24, bone plate portion 204 is attached to humerus H toprovide a rigid structure for attaching head portion 202 thereto. Therigid structure provided by the attachment of bone plate portion 204 tothe humerus H allows head portion 202 to be secured in position onhumerus H.

As depicted in FIG. 5, bone plate portion 204 is attached to humerus H,and includes a first portion 206 and a second portion 208. First portion206 is used in attaching bone plate portion 204 to humerus H at oradjacent surgical neck SN, and second portion 208 is used in attachingbone plate portion 204 to at least one of greater or lesser tubercles T.Bone plate portion 204 includes a length and a longitudinal axisextending between a first end 210 and a second end 212. Furthermore,like the width of bone plate portion 24, the width (i.e., the dimensionsperpendicular to the length) of bone plate portion 204 can vary alongthe length thereof to facilitate contact with different portions ofhumerus H. For example, second portion 208 can be wider than firstportion 206 to accommodate contact thereof with both of greater andlesser tubercles T. An illustrative shape for the perimeter of boneplate portion 204 can be seen in FIG. 7.

Like bone plate portion 24, bone plate portion 204 includes both anupper surface 214 and a lower surface 216 extending along first andsecond portions 206 and 208. Like lower surface 36 of first and secondportions 26 and 28, lower surface 216 of first and second portions 206and 208 can be contoured to contact different portions of humerus H.

Furthermore, although not depicted in FIG. 5, first portion 206 caninclude apertures (similar to apertures 42) extending between upper andlower surfaces 214 and 216 that are configured for receiving fastenerssuch as bone screws 40. Like first portion 26 of bone plate portion 24,first portion 206 of bone plate portion 204 can be attached at oradjacent surgical neck SN using bone screws 40. Bone screws 40 canengage the apertures formed in first portion 206, as well as apertures(not shown) formed in humerus H.

Second portion 208 of bone plate portion 204 is configured to receiveone or more fasteners 220 therethrough to facilitate attachment of headportion 202, bone plate portion 204, and humerus H to one another. Tothat end, second portion 208 can include one or more apertures 222therethrough (extending between upper and lower surfaces 214 and 216)for receiving fasteners 220. Fasteners 220 can each include a shaft 224and a head 226. Shafts 224 can serve in facilitating engagement withhead portion 202 and humerus H, and heads 226 can serve in facilitatingengagement with second portion 208. When lower surface 216 (at secondportion 208) is properly positioned with respect to humerus H, fasteners220 can be inserted into apertures 222, into apertures 230 formed inhumerus H, and into apertures 232 formed in head portion 202.Furthermore, apertures 222 can be countersunk to receive heads 226, sothat at least portions of heads 226 ultimately can lie below uppersurface 214.

Three fasteners 220 and three apertures 222 are depicted in FIG. 5arranged to have oblique orientations with respect to one another.Fasteners 220 and apertures 222 are spaced along the longitudinal axisof bone plate portion 204. However, given the spacing thereof along thelongitudinal axis of bone plate 204, apertures 222 would be oriented sothat fasteners 220 are also angled differently into and out of the pagedefined by FIG. 5, so as to avoid interference with one another. Assuch, given such orientations of apertures 222, the fasteners 220 canhave a crisscrossed orientation as depicted in FIG. 5.

Furthermore, in similar fashion to apertures 52 (and correspondingfasteners 50) of first humeral head replacement system 20, the number,arrangement, spacing, and orientation of apertures 222 (and hence,corresponding fasteners 220) can vary further.

Like with first humeral head replacement system 20, these variations(such as the positioning thereof on either side of the longitudinal axisand pattern formed thereby) for apertures 222 (and correspondingfasteners 220) can occur because second portion 208 is sized to contactvarying portions of humerus H, and the desire to have the fasteners 220parallelly or obliquely oriented with respect to one another.

Like shafts 54 and heads 56, shafts 224 and heads 226 can be configuredto have cylindrical or frusto-conical shaped portions, and have regularroughened surfaces, irregular roughened surfaces, and/or smoothenedsurfaces provided on the cylindrical or frusto-conical shaped portions.Furthermore, like shafts 54, shafts 224 can include first portions 224Aused in engaging apertures 230 formed through humerus H, and secondportions 224B used in engaging corresponding surfaces of apertures 232formed in head portion 202. First and second portions 224A and 224B canbe configured to have identical or different shapes, lengths, andwidths, and can include the above-discussed regular roughened surfaces,irregular roughened surfaces, and/or smoothened surfaces.

The connection between head portion 202 and bone plate portion 204afforded by fasteners 220 serves in maintaining the positions of thecomponents of humeral head replacement system 200 relative to humerus H.Indeed, portions of humerus H are clamped between head portion 202 andbone plate portion 204. Furthermore, in addition to the connectionbetween head portion 202 and bone plate portion 204 afforded thereby,the configuration of fasteners 220 can serve in resisting movement (andhence, maintaining the position) of the components of humeral headreplacement system 200 relative to humerus H. That is, the regular orirregular roughened surfaces formed on shafts 224 can serve in fixingfasteners 220 relative to humerus H. For example, if first portions 224Ainclude threads/ratchets 236, threads/ratchets 236 would resist linearrearward movement (or backing out) of fasteners 220 from apertures 230.

Head portion 202, as depicted in FIG. 5, is generally shaped as asubstantially semi-hollow spherical cap. Head portion 202 includes anarticular surface 240, an interior surface 241, a bone-contacting rim242, an interior cavity 243 delineated at least in part by interiorsurface 241 and bone-contacting rim 242, and columns 244, 246, and 248extending outwardly from interior surface 241 into interior cavity 243.Articular surface 240 is substantially similar to the shape of thearticular surface of the humeral head (or portions thereof) for which itis used in replacing. The thickness of head portion 202 betweenarticular and interior surfaces 240 and 241 can vary. As depicted inFIG. 5, bone-contacting rim 242 is formed at a base 250 of head portion202, and contacts surface S₆ of humerus H. Bone-contacting rim 242 canbe configured to accommodate the shape of surface S₆, and surface S₆ canbe prepared to interface with the shape of bone-contacting rim 242.

Columns 244, 246, and 248 include apertures 232 for receiving fasteners220, and unfractured bone of humerus H, bone fragments of humerus H,and/or a substrate (not shown) can fill interior cavity 243. Theunfractured bone of humerus H, the bone fragments of the humerus H,and/or the substrate can be provided between base 250, and interiorsurface 241 and columns 244, 246, and 248. When interior cavity 243 isfilled with the unfractured bone of humerus H, the bone fragments of thehumerus H, and/or the substrate, apertures 230 would extend through theunfractured bone of humerus H, the bone fragments of humerus H, and/orthe substrate provided therein. As depicted in FIG. 5, the unfracturedbone of humerus H fills interior cavity 243. As such, apertures 230extend through the unfractured bone of humerus H filling interior cavity243. Furthermore, apertures 230 and 232 abut one another, and surface S₇of humerus H contacts interior surface 241. Surface S₇ can be preparedto interface with the shape of interior surface 241, and vice versa.

Columns 244, 246, and 248 can have different orientations with respectto one another to accommodate the desired orientations of fasteners 220.Furthermore, columns 244, 246, and 248 can have different heights withrespect to interior surface 241 of head portion 202. As such, columns244, 246, and 248 can be extended toward base 250, and, provided thatthere is no interference therebetween, columns 244, 246, and 248 canhave markedly different orientations and heights. Columns 244, 246, and248, as depicted in FIG. 5, are oriented at angles in accordance withthe angles of fasteners 220. While the heights of columns 244, 246, and248 depicted in FIG. 5 have short profiles relative to interior surface241, columns 244, 246, and 248 can instead have tall profiles relativeto interior surface 241.

Depending on whether second portions 224B have regular roughenedsurfaces, irregular roughened surfaces, and/or smoothened surfaces,engagement of fasteners 220 to head portion 202 would be different. Forexample, if second portions 224B include threads/ratchets 256, secondportions 224B can engage (via complimentary structures formed in and/orvia interference, press, and/or friction fits with) apertures 232.Furthermore, if second portions 224B have smoothened surfaces, secondportions 224B can engage (via interference, press, and/or friction fits)surfaces formed in apertures 232. The interactions afforded by thecomplimentary structures and interference, press, and/or friction fitsserve in attaching fasteners 220 to head portion 202 by resisting linearmovement (or backing out) of fasteners 220 from head portion 202 afterinsertion into apertures 232.

Fifth humeral head replacement system 260 is depicted in FIG. 6 inposition with respect to humerus H. Humeral head replacement system 260includes a head or prosthetic portion 262 and a bone plate portion 264.Like head portion 22, head portion 262 serves as a prosthesis forreplacement of the humeral head or portions thereof, and, like boneplate portion 24, bone plate portion 264 is attached to humerus H toprovide a rigid structure for attaching head portion 262 thereto. Therigid structure provided by the attachment of bone plate portion 264 tohumerus H allows head portion 262 to be secured in position on humerusH.

As depicted in FIG. 6, bone plate portion 264 is attached to humerus H,and includes a first portion 266 and a second portion 268. First portion266 is used in attaching bone plate portion 264 to humerus H at oradjacent surgical neck SN, and second portion 268 is used in attachingbone plate portion 264 to at least one of greater or lesser tubercles T.Bone plate portion 264 includes a length and a longitudinal axisextending between a first end 270 and a second end 272. Furthermore,like the width of bone plate portion 24, the width (i.e., the dimensionsperpendicular to the length) of bone plate portion 264 can vary alongthe length thereof to facilitate contact with different portions ofhumerus H. For example, second portion 268 can be wider than firstportion 266 to accommodate contact thereof with both of greater andlesser tubercles T. An illustrative shape for the perimeter of boneplate portion 264 can be seen in FIG. 7.

Like bone plate portion 24, bone plate portion 264 includes both anupper surface 274 and a lower surface 276 extending along first andsecond portions 266 and 268. Like lower surface 36 of first and secondportions 26 and 28, lower surface 276 of first and second portions 266and 268 can be contoured to contact different portions of humerus H.

Furthermore, although not depicted in FIG. 6, first portion 266 caninclude apertures (similar to apertures 42) extending between upper andlower surfaces 274 and 276 that are configured for receiving fastenerssuch as bone screws 40. Like first portion 26 of bone plate portion 24,first portion 266 of bone plate portion 264 can be attached at oradjacent surgical neck SN using bone screws 40. Bone screws 40 canengage the apertures formed in first portion 266, as well as apertures(not shown) formed in humerus H.

Second portion 268 of bone plate portion 264 is configured to receiveone or more fasteners 280 therethrough to facilitate attachment of headportion 262, bone plate portion 264, and humerus H to one another. Tothat end, second portion 268 can include one or more apertures 282therethrough (extending between upper and lower surfaces 274 and 276)for receiving fasteners 280. Fasteners 280 can each include a shaft 284and a head 286. Shafts 284 can serve in facilitating engagement withhead portion 262 and humerus H, and heads 286 can serve in facilitatingengagement with second portion 268. When lower surface 276 (at secondportion 268) is properly positioned with respect to humerus H, fasteners280 can be inserted into apertures 282, into apertures 290 formed inhumerus H, and into apertures 292 formed in head portion 262.Furthermore, apertures 282 can be countersunk to receive heads 286, sothat at least portions of heads 286 ultimately can lie below uppersurface 274.

Three fasteners 280 and three apertures 282 are depicted in FIG. 6arranged to have a generally parallel orientation with respect to oneanother. Fasteners 280 and apertures 282 are spaced along thelongitudinal axis of bone plate portion 264. Furthermore, in similarfashion to apertures 52 (and corresponding fasteners 50) of firsthumeral head replacement system 20, the number, arrangement, spacing,and orientation of apertures 282 (and hence, corresponding fasteners280) can vary further. Like with first humeral head replacement system20, these variations (such as the positioning thereof on either side ofthe longitudinal axis and pattern formed thereby) for apertures 282 (andcorresponding fasteners 280) can occur because second portion 268 issized to contact varying portions of humerus H, and the desire to havethe fasteners 280 parallelly or obliquely oriented with respect to oneanother.

Like shafts 54 and heads 56, shafts 284 and heads 286 can be configuredto have cylindrical or frusto-conical shaped portions, and have regularroughened surfaces, irregular roughened surfaces, and/or smoothenedsurfaces provided on the cylindrical or frusto-conical shaped portions.Furthermore, like shafts 54, shafts 284 can include first portions 284Aused in engaging apertures 290 formed through humerus H, and secondportions 284B used in engaging corresponding surfaces of apertures 292formed in head portion 262. First and second portions 284A and 284B canbe configured to have identical or different shapes, lengths, andwidths, and can include the above-discussed regular roughened surfaces,irregular roughened surfaces, and/or smoothened surfaces.

The connection between head portion 262 and bone plate portion 264afforded by fasteners 280 serves in maintaining the positions of thecomponents of humeral head replacement system 260 relative to humerus H.Indeed, portions of humerus H are clamped between head portion 262 andbone plate portion 264. Furthermore, in addition to the connectionbetween head portion 262 and bone plate portion 264 afforded thereby,the configuration of fasteners 280 can serve in resisting movement (andhence, maintaining the position) of the components of humeral headreplacement system 260 relative to humerus H. That is, the regular orirregular roughened surfaces formed on shafts 284 can serve in fixingfasteners 280 relative to humerus H. For example, if first portions 284Ainclude threads/ratchets 296, threads/ratchets 296 would resist linearrearward movement (or backing out) of fasteners 280 from apertures 290.

Head portion 262, as depicted in FIG. 6, is generally shaped as asubstantially semi-hollow spherical cap. Head portion 262 includes anarticular surface 300, an interior surface 301, a bone-contacting rim302, an interior cavity 303 delineated at least in part by interiorsurface 301 and bone-contacting rim 302, and columns 304, 306, and 308extending outwardly from interior surface 301 into interior cavity 303.Articular surface 300 is substantially similar to the shape of thearticular surface of the humeral head (or portions thereof) for which itis used in replacing. The thickness of head portion 262 betweenarticular and interior surfaces 300 and 301 can vary. As depicted inFIG. 6, bone-contacting rim 302 is formed at a base 310 of head portion262, and contacts surface S₈ of humerus H. Bone-contacting rim 302 canbe configured to accommodate the shape of surface S₈, and surface S₈ canbe prepared to interface with the shape of bone-contacting rim 302.

Columns 304, 306, and 308 include apertures 292 for receiving fasteners280. Like columns 244, 246, and 248, columns 304, 306, and 308 can havedifferent orientations with respect to one another, and can havedifferent heights with respect to interior surface 301 of head portion262. Columns 304, 306, and 308, as depicted in FIG. 6, extend frominterior surface 301 to terminate adjacent base 310. As such, surfaces314, 316, and 318 of columns 304, 306, and 308, respectively, contactsurface S₉ of humerus H. Furthermore, columns 304, 306, and 308 depictedin FIG. 6 have generally parallel orientations with respect to oneanother, and have different heights relative to interior surface 301.Although not depicted in FIG. 6, unfractured bone of humerus H, bonefragments of humerus H, and/or a substrate can be provided in interiorcavity 303 around columns 304, 306, 308, and can extend from base 310 tointerior surface 301.

Depending on whether second portions 284B have regular roughed surfaces,irregular roughened surfaces, and/or smoothened surfaces, engagement offasteners 280 to head portion 262 would be different. The configurationof apertures 292 formed in columns 304, 306, and 308 would be configuredto accommodate the regular roughened surfaces, irregular roughenedsurfaces, and/or smoothened surfaces formed on second portions 284B. Forexample, apertures 292 of head portion 262 depicted in FIG. 6 havethreads/ratchets 320 to engage threaded/ratchets 326 formed on secondportions 284B; and apertures 292 of head portion 262A depicted in FIG.6A have smoothened surfaces 322 to engage smoothened surfaces 328 formedon second portions 284B. The interactions afforded by the complimentarystructures and interference, press, and/or friction fits serve inattaching fasteners 280 to head portions 262 and 262A by resistinglinear movement (or backing out) of fasteners 280 from head portion 262after insertion into apertures 292.

As depicted in FIGS. 6 and 6A, for example, apertures 292 andcorresponding fasteners 280 are sized similarly. However, one of moredifferently sized fasteners can be used for attaching a head portion, abone plate portion, and humerus H in the humeral head replacementsystems described herein.

Sixth humeral head replacement system 340 depicted in FIG. 7 uses suchdifferently sized fasteners. Humeral head replacement system 340includes a head or prosthetic portion 342 and a bone plate portion 344.Head portion 342 and bone plate portion 344 function similarly to andcan include the features of head portion 262 and bone plate portion 264of humeral head replacement system 260. However, rather than includingsimilarly sized fasteners for attaching head portion 342, bone plateportion 344, and humerus H to one another, humeral head replacementsystem 340 includes at least one oversized fastener 350 to facilitatesuch attachment. Oversized fastener 350 and additional fasteners (notshown) of humeral head replacement system 340 can function similarly toand include the features of fasteners 280 of humeral head replacementsystem 260.

Bone plate portion 344 includes an aperture 352 for receiving oversizedfastener 350, and apertures 354 for receiving the additional fastenershaving smaller diameters than oversized fastener 350. As depicted inFIG. 7, apertures 354 have a diamond-shaped pattern surrounding aperture352. However, like apertures 282, the number, arrangement, spacing, andorientation of apertures 352 and 354 can vary. Head portion 342 includesapertures 356 and 358 corresponding to apertures 352 and 354,respectively. That is, aperture 356 can receive oversized fastener 350,and apertures 358 can receive the additional fasteners. Apertures 356and 358, as depicted in FIG. 7, are formed in columns 360 and 362,respectively.

Depending on the configurations of oversized fastener 350 and additionalfasteners, engagement with humerus and apertures 356 and 358,respectively, would be different. Like fasteners 280, fastener 305 andadditional fasteners could include regular roughened surfaces, irregularroughened surfaces, and smoothened surfaces to engage humerus H, andengage complimentary structures and/or engage (via interference, press,and/or friction fits) surfaces formed in apertures 356 and 358.

Seventh humeral head replacement system 380 is depicted in FIG. 8 inposition with respect to humerus H. Humeral head replacement system 380includes a head or prosthetic portion 382 and a bone plate portion 384.Like head portion 22, head portion 382 serves as a prosthesis forreplacement of the humeral head or portions thereof, and, like boneplate portion 24, bone plate portion 384 is attached to humerus H toprovide a rigid structure for attaching head portion 382 thereto. Therigid structure provided by the attachment of bone plate portion 384 tohumerus H allows head portion 382 to be secured in position on humerusH.

As depicted in FIG. 8, bone plate portion 384 is attached to humerus H,and includes a first portion 386 and a second portion 388. First portion386 is used in attaching bone plate portion 384 to humerus H at oradjacent surgical neck SN, and second portion 388 is used in attachingbone plate portion 384 to at least one of greater or lesser tubercles T.Bone plate portion 384 includes a length and a longitudinal axisextending between a first end 390 and a second end 392. Furthermore,like the width of bone plate portion 24, the width (i.e., the dimensionsperpendicular to the length) of bone plate portion 384 can vary alongthe length thereof to facilitate contact with different portions ofhumerus H. For example, second portion 388 can be wider than firstportion 386 to accommodate contact thereof with both of greater andlesser tubercles T. An illustrative shape for the perimeter of boneplate portion 384 can be seen in FIG. 7.

Like bone plate portion 24, bone plate portion 384 includes both anupper surface 394 and a lower surface 396 extending along first andsecond portions 386 and 388. Like lower surface 36 of first and secondportions 26 and 28, lower surface 396 of first and second portions 386and 388 can be contoured to contact different portions of humerus H.

Furthermore, although not depicted in FIG. 8, first portion 386 caninclude apertures (similar to apertures 42) extending between upper andlower surfaces 394 and 396 that are configured for receiving fastenerssuch as bone screws 40. Like first portion 26 of bone plate portion 24,first portion 386 of bone plate portion 384 can be attached at oradjacent surgical neck SN using bone screws 40. Bone screws 40 canengage the apertures formed in first portion 386, as well as apertures(not shown) formed in humerus H.

In addition to first portion 386 being attached at or adjacent surgicalneck SN using fasteners such as bone screws 40, second portion 388 canbe configured to receive one or more of fasteners such as bone screws 40therethrough to attach second portion 388 above surgical neck SN. Asdepicted in FIG. 8, second portion 388 includes apertures 400 extendingbetween upper and lower surfaces 394 and 396 for receiving bone screws40, and humerus H includes apertures 402 for receiving bone screws 40.Threaded shafts 44 (of bone screws 40) can serve in facilitatingengagement with apertures 402 formed in humerus H, and threaded heads 46(of bone screws 40) can serve in facilitating engagement with secondplate portion 388 via complimentary threads (not shown) provided inapertures 400. When lower surface 396 (at first portion 386) is properlypositioned with respect to humerus H, bone screws 40 can be insertedinto apertures 400 and into humerus H to further secure bone plateportion 384 to humerus H. Furthermore, apertures 400 can be countersunkto receive threaded heads 46, so that at least portions of threadedheads 46 ultimately can lie below upper surface 394.

Rather than or in addition to using fasteners (such as fasteners 50 ofhumeral head replacement system 20), bone plate portion 384 can includeone or more integrally formed posts for insertion into a portion of headportion 382. As depicted in FIG. 8, bone plate portion 384 includes apost 404 extending outwardly from lower surface 396 (at second portion388). Post 404 can be used to facilitate attachment of head portion 382,bone plate portion 384, and humerus H to one another.

Post 404 includes a first shaft portion 406 and a second shaft portion408. First shaft portion 406 can serve in facilitating engagement withan aperture 410 formed in humerus H, and second shaft portion 408 canserve in facilitating engagement with an aperture 412 formed in headportion 382. In essence, second shaft portion 408 of post 404 serves asa male component to be received in a female component afforded byaperture 412 formed in head portion 382. During positioning of headportion 382 and bone plate portion 384 with respect to humerus H, post404 can be inserted into aperture 410 formed in humerus H, and intoaperture 412 formed in head portion 382. As discussed below, post 404and aperture 412 can include regular roughened surfaces, irregularroughened surfaces, and/or smoothened surfaces to facilitate aconnection therebetween.

As discussed above, one or more posts 404 can be formed on bone plateportion 384. For example, multiple posts 404 can be spaced along thelongitudinal axis of bone plate portion 384. Furthermore, in similarfashion to apertures 52 (and corresponding fasteners 50) of firsthumeral head replacement system 20, the number, arrangement, and spacingof multiple posts 404 can vary further. Like with apertures 52 (andcorresponding fasteners 50) of first humeral head replacement system 20,these variations (such as the positioning thereof on either side of thelongitudinal axis and pattern formed thereby) for multiple posts 404 canoccur because second portion 388 is sized to contact varying portions ofhumerus H. These variations can also occur because the desire to havemultiple posts 404 obliquely oriented with respect to head portion382—multiple posts 404 would likely be parallel or close to parallel toone another to afford engagement with head portion 382.

Like first and second portions 54A and 54B of shafts 54, first andsecond shaft portions 406 and 408 of post 404 can be configured to havecylindrical or frusto-conical shaped portions, and have regularroughened surfaces, irregular roughened surfaces, and/or smoothenedsurfaces provided on the cylindrical or frusto-conical shaped portionsfor engaging corresponding surfaces provided in apertures 410 and 412.

As depicted in FIG. 8, the connection between head portion 382 and boneplate portion 384 afforded by the interaction between the surfaces ofpost 404 and aperture 412 serves in maintaining the positions of thecomponents of humeral head replacement system 380 relative to humerus H.Indeed, portions of humerus H are clamped between head portion 382 andbone plate portion 384. Furthermore, the configuration of post 404 canserve in resisting movement (and hence, maintaining the position) of thecomponents of humeral head replacement system 380 relative to humerus H.For example, if first shaft portion 406 includes threads/ratchets (notshown), the threads/ratchets would resist linear rearward movement (orbacking out) of post 404 from aperture 410, and, in doing so, serve infixing post 404 relative to humerus H.

As depicted in FIG. 8, head portion 382 is generally shaped as asubstantially semi-hollow spherical cap. Head portion 382, as depictedin FIG. 8, includes an articular surface 416, an interior surface 418, abone-contacting rim 420, an interior cavity 422, and a column 424.Articular surface 416 is substantially similar to the shape of thearticular surface of the humeral head (or portions thereof) for which itis used in replacing. Head portion 382, however, is not limited to thefeatures depicted in FIG. 8. Where compatible, head portion 382 couldinstead include the features of the other head portions describedherein.

As depicted in FIG. 8, interior cavity 422 is provided at least in partbetween interior surface 418 and bone-contacting rim 420, and column 424is depicted extending outwardly from interior surface 418 into interiorcavity 422. The thickness of head portion 382 between articular andinterior surfaces 416 and 418 can vary. As depicted in FIG. 8,bone-contacting rim 420 is formed at a base 426 of head portion 382, andcontacts surface S₁₀ of humerus H. Bone-contacting rim 420 can beconfigured to accommodate the shape of surface S₁₀, and surface S₁₀ canbe prepared to interface with the shape of bone-contacting rim 420.Moreover, although not depicted in FIG. 8, unfractured bone of humerusH, bone fragments of humerus H, and/or a substrate can be provided ininterior cavity 422 around column 424, and can extend from base 426 tointerior surface 418.

As discussed above, column 424 includes aperture 412 for receivingsecond shaft portion 408 of post 404. Column 424 can have varyingorientations to accommodate the orientation of post 404, and can havevarying heights with respect to interior surface 418 of head portion382. Column 424, as depicted in FIG. 8, extends from interior surface418 to terminate beyond base 426. As such, surface 428 of column 424contacts surface S₁₁ of humerus H. Furthermore, if multiple posts 404are formed on bone plate portion 384, multiple columns 424 andcorresponding apertures 412 can be provided to receive multiple posts404, and multiple columns 424 can have different heights with respect tointerior surface 418 of head portion 382.

Depending on whether second shaft portion 408 of post 404 has regularroughed surfaces, irregular roughened surfaces, and/or smoothenedsurfaces, engagement of post 404 to head portion 382 would be different.Aperture 412 formed in column 424 would be configured to accommodate theregular roughened surfaces, irregular roughened surfaces, and/orsmoothened surfaces formed on second shaft portion 408. For example, ifsecond shaft portion 408 includes threads/ratchets (not shown), secondshaft portion 408 can engage (via complimentary structures formed inand/or via interference, press, and/or friction fits with) aperture 412.Furthermore, if second shaft portion 408 has a smoothened surface 430,second shaft portion 408 can engage (via interference, press, and/orfriction fits) a smoothened surface 432 formed in aperture 412. Theinteractions afforded by the complimentary structures and interference,press, and/or friction fits serve in attaching post 404 to head portion382 by resisting linear movement (or backing out) of post 404 from headportion 382 after insertion into aperture 412.

Eighth humeral head replacement system 440 is depicted in FIG. 9 inposition with respect to humerus H. Humeral head replacement system 440includes a head or prosthetic portion 442 and a bone plate portion 444.Like the head portion 22, head portion 442 serves as a prosthesis forreplacement of the humeral head or portions thereof, and, like boneplate portion 24, bone plate portion 444 is attached to humerus H toprovide a rigid structure for attaching head portion 442 thereto. Therigid structure provided by the attachment of bone plate portion 444 tothe humerus H allows head portion 442 to be secured in position onhumerus H.

As depicted in FIG. 9, bone plate portion 444 is attached to humerus H,and includes a first portion 446 and a second portion 448, and includesboth an upper surface 450 and a lower surface 452 extending along firstand second portions 446 and 448. Bone plate portion 444 can include manyof the features of above-discussed bone plate portion 384. As such,first portion 446 can be attached at or adjacent surgical neck SN insimilar fashion to first portion 386 of bone plate portion 384, andsecond portion 448 can be attached to at least one of greater or lessertubercles T above surgical neck SN.

However, instead of post 404, bone plate portion 444 includes one ormore integrally formed posts for receiving a portion of head portion442. As depicted in FIG. 9, bone plate portion 444 includes a post 454extending outwardly from lower surface 452 (at second portion 448). Post454 can be used to facilitate attachment of head portion 442, bone plateportion 444, and humerus H to one another.

Post 454 includes a first shaft portion 456 and a second shaft portion458. First and second shaft portions 456 and 458 can include thefeatures of first and second shaft portions 406 and 408 of post 404. Assuch, first and second shaft portions 456 and 458 can be configured tohave cylindrical or frusto-conical shaped portions, and have regularroughened surfaces, irregular roughened surfaces, and/or smoothenedsurfaces provided on the cylindrical or frusto-conical shaped portions.

First shaft portion 456 can serve in facilitating engagement with anaperture 460 formed in humerus H, and second shaft portion 458 includesa depression (or aperture) 462 serving to facilitate engagement with acolumn 464 formed on head portion 442. In essence, depression 462 formedin post 454 serves as a female component for receipt of a male componentafforded by column 464 formed on head portion 442. During positioning ofhead portion 442 and bone plate portion 444 with respect to humerus H,post 454 can be inserted into aperture 460 formed in humerus H.Thereafter, column 464 of head portion 442 can be inserted intodepression 462 formed in post 454. As discussed below, depression 462and column 464 can include regular roughened surfaces, irregularroughened surfaces, and/or smoothened surfaces to facilitate aconnection therebetween. Furthermore, to further secure the connectiontherebetween, post 454 and column 464 can include apertures 470 and 472,respectively, for receiving a fastener 474. Aperture 470 extends intopost 454 from depression 462, and aperture 472 extends through column464.

As discussed above, one or more posts 454 can be formed on bone plateportion 444. For example, multiple posts 454 can be spaced alonglongitudinal axis of bone plate portion 444. Furthermore, in similarfashion to apertures 52 (and corresponding fasteners 50) of firsthumeral head replacement system 20, the number, arrangement, and spacingof multiple posts 454 can vary further. Like with apertures 52 (andcorresponding fasteners 50) of first humeral head replacement system 20,these variations (such as the positioning thereof on either side of thelongitudinal axis and pattern formed thereby) for multiple posts 454 canoccur because second portion 448 is sized to contact varying portions ofhumerus H. These variations can also occur because of the desire to havemultiple posts 454 obliquely oriented with respect to head portion442—multiple posts 454 would likely be parallel or close to parallel toone another to afford engagement with head portion 442.

As depicted in FIG. 9, the connection between head portion 442 and boneplate portion 444 afforded by the interaction between the surfaces ofdepression 462 and column 464 serves in maintaining the positions of thecomponents of humeral head replacement system 440 relative to humerus H.Indeed, portions of humerus H are clamped between head portion 442 andbone plate portion 444. Furthermore, the configuration of post 454 canserve in resisting movement (and hence, maintaining the position) of thecomponents of humeral head replacement system 440 relative to humerus H.For example, if first shaft portion 456 includes threads/ratchets (notshown), the threads/ratchets would resist linear rearward movement (orbacking out) of post 454 from aperture 460, and, in doing so, serve infixing post 454 relative to humerus H.

As depicted in FIG. 9, head portion 442 is generally shaped as asubstantially semi-hollow spherical cap. Head portion 442, as depictedin FIG. 9, includes an articular surface 476, an interior surface 478, abone-contacting rim 480, an interior cavity 482, column 464, andaperture 472 formed through column 464. Articular surface 476 issubstantially similar to the shape of the articular surface of thehumeral head (or portions thereof) for which it is used in replacing.Furthermore, head portion 442 can include an aperture 484 formed inarticular surface 476 and interconnected with aperture 472. Head portion442, however, is not limited to the features depicted in FIG. 9. Wherecompatible, head portion 442 could instead include the features of theother head portions described herein.

As depicted in FIG. 9, interior cavity 482 is provided in least in partbetween interior surface 478 and bone-contacting rim 480, and column 464is depicted extending outwardly from interior surface 478 into interiorcavity 482. The thickness of head portion 442 between articular andinterior surfaces 476 and 478 can vary. As depicted in FIG. 9,bone-contacting rim 480 is formed at a base 486 of head portion 442, andcontacts surface S₁₂ of humerus H. Bone-contacting rim 480 can beconfigured to accommodate the shape of surface S₁₂, and surface S₁₂ canbe prepared to interface with the shape of bone-contacting rim 480.Moreover, although not depicted in FIG. 9, unfractured bone of humerusH, bone fragments of humerus H, and/or a substrate can be provided ininterior cavity 482 around column 464, and can extend from base 486 tointerior surface 478.

As discussed above, column 464 is received in depression 462 formed inpost 454. Column 464 can have varying orientations to accommodate theorientation of post 454, and can have varying heights with respect tointerior surface 478 of head portion 442. Column 464, as depicted inFIG. 9, extends from interior surface 478 to terminate beyond base 486.Furthermore, if multiple posts 454 are formed on bone plate portion 444,multiple columns 464 can be provided to be received in correspondingmultiple depressions 462 of multiple posts 454, and multiple columns 464can have different heights with respect to interior surface 478 of headportion 442.

Depending on whether depression 462 of post 454 has regular roughedsurfaces, irregular roughened surfaces, and/or smoothened surfaces,engagement of head portion 442 to post 454 would be different. Column464 would be correspondingly configured to accommodate the regularroughened surfaces, irregular roughened surfaces, and/or smoothenedsurfaces formed in depression 462. For example, if depression 462includes threads/ratchets (not shown), depression 462 can (engage viacomplimentary structures formed on and/or via interference, press,and/or friction fits with) column 464. Furthermore, if depression 462has a smoothened surface 490, depression 462 can engage (viainterference, press, and/or friction fits) a smoothened surface 492formed on column 464. The interactions afforded by the complimentarystructures and interference, press, and/or friction fits serve inattaching head portion 442 to post 454 of bone plate portion 444 byresisting linear movement (or backing out) of column 464 of head portion442 from depression 462 of post 454.

As discussed above, fastener 474 can be used to further secure headportion 442 and bone plate portion 444 to one another. As depicted inFIG. 9, when column 464 is received in depression 462 of post 454,aperture 470 formed in post 454, aperture 472 formed in column 464, andaperture 484 formed in articular surface 476 are aligned with oneanother. Such alignment allows fastener 474 to be inserted throughaperture 484 and into apertures 470 and 472. A shoulder 494 can beprovided in aperture 472 formed in column 464 to contact fastener 474 toprevent further insertion. Furthermore, fastener 474 can include regularroughened surfaces, irregular roughened surfaces, and/or smoothenedsurfaces 496 to interact with a corresponding surfaces 498 provided inaperture 470 to further secure head portion 442 and bone plate portion444.

Ninth humeral head replacement system 510 is depicted in FIG. 10 inposition with respect to humerus H. Humeral head replacement system 510includes a head or prosthetic portion 512, a bone plate portion 514, andan intermediate portion 515. Like head portion 22, head portion 512serves as a prosthesis for replacement of the humeral head or portionsthereof, and, like bone plate portion 24, bone plate portion 514 isattached to humerus H to provide a rigid structure for attachingintermediate portion 515 thereto. Intermediate portion 515 can beprovided within humerus H and attached to bone plate portion 514 toprovide a rigid structure for attaching head portion 512 thereto. Therigid structure provided by bone plate portion 514 and intermediateportion 515 allows head portion 512 to be secured in position on humerusH.

As depicted in FIG. 10, bone plate portion 514 is attached to humerus H,and includes a first portion 516 and a second portion 518. First portion516 is used in attaching bone plate portion 514 to humerus H at oradjacent surgical neck SN, and second portion 518 is used in attachingbone plate portion 514 to at least one of greater or lesser tubercles T.Bone plate portion 514 includes a length and a longitudinal axisextending between a first end 520 and a second end 522. Furthermore,like the width of bone plate portion 24, the width (i.e., the dimensionsperpendicular to the length) of bone plate portion 514 can vary alongthe length thereof to facilitate contact with different portions ofhumerus H. For example, second portion 518 can be wider than firstportion 516 to accommodate contact thereof with both of greater andlesser tubercles T. An illustrative shape for the perimeter of boneplate portion 514 can be seen in FIG. 7.

Like bone plate portion 24, bone plate portion 514 includes both anupper surface 524 and a lower surface 526 extending along first andsecond portions 516 and 518. Like lower surface 36 of first and secondportions 26 and 28, lower surface 526 of first and second portions 516and 518 can be contoured to contact different portions of humerus H.

Furthermore, although not depicted in FIG. 10, first portion 516 caninclude apertures (similar to apertures 42) extending between upper andlower surfaces 524 and 526 that are configured for receiving fastenerssuch as bone screws 40. Like first portion 26 of bone plate portion 24,first portion 516 of bone plate portion 514 can be attached at oradjacent surgical neck SN using bone screws 40. Bone screws 40 canengage the apertures formed in first portion 516, as well as apertures(not shown) formed in humerus H.

Second portion 518 of bone plate portion 514 is configured to receiveone or more fasteners 530 therethrough. Fasteners 530 are used tofacilitate attachment of intermediate portion 515 and bone plate portion514 to one another. In addition, fasteners 530 can engage humerus H, andcan also be used to secure humerus H between bone plate portion 514 andintermediate portion 515. To those ends, second portion 518 can includeone or more apertures 532 therethrough (extending between upper andlower surfaces 524 and 526) for receiving fasteners 530.

Fasteners 530 can each include a shaft 534 and a head 536. Shafts 534can serve in facilitating engagement with intermediate portion 515 andhumerus H, and heads 536 can serve in facilitating engagement withapertures 532 of second portion 518. When lower surface 526 (at secondportion 518) is properly positioned with respect to humerus H, fasteners530 can be inserted into apertures 532, into apertures 540 formed inhumerus H, and into apertures 542 formed in intermediate portion 515.Furthermore, apertures 532 can be countersunk to receive heads 536, sothat at least portions of heads 536 ultimately can lie below uppersurface 524.

Three fasteners 530 and three apertures 532 are depicted in FIG. 10arranged to have a generally parallel orientation with respect to oneanother. Fasteners 530 and apertures 532 are spaced along thelongitudinal axis of bone plate portion 514. Furthermore, in similarfashion to apertures 52 (and corresponding fasteners 50) of firsthumeral head replacement system 20, the number, arrangement, spacing,and orientation of apertures 532 (and hence, corresponding fasteners530) can vary further. Like with first humeral head replacement system20, these variations (such as the positioning thereof on either side ofthe longitudinal axis and pattern formed thereby) for apertures 532 (andcorresponding fasteners 530) can occur because second portion 518 issized to contact varying portions of humerus H, and the desire to havethe fasteners 530 parallelly or obliquely oriented with respect to oneanother.

Like shafts 54 and heads 56, shafts 534 and heads 536 can be configuredto have cylindrical or frusto-conical shaped portions, and have regularroughened surfaces, irregular roughened surfaces, and/or smoothenedsurfaces provided on the cylindrical or frusto-conical shaped portions.Furthermore, apertures 532 can include corresponding surfaces tofacilitate engagement with heads 536, and apertures 540 and 542 caninclude corresponding surfaces to facilitate engagement with shafts 534.As such, fasteners 530 can interact with apertures 532, 540, and 542 toattach bone plate portion 514, intermediate portion 515, and humerus Htogether.

Intermediate portion 515 includes a flange (or plate) portion 550 and apost 552 extending outwardly from flange portion 550. Flange portion 550can be frusto-conical, and includes a first surface 556, second surface558, and an edge surface 560 extending between first surface 556 andsecond surface 558. Apertures 542 are formed through first surface 556and extend into flange portion 550. The number, arrangement, spacing,and orientation of apertures 542 can correspond to the same of apertures532 formed in bone plate portion 514. Given that flange portion 550 isfrusto-conical, the thickness thereof increases from edge surface 560toward the center of flange portion 550.

Post 552 can be integrally formed with flange portion 550. Furthermore,post 552 can include a first shaft portion 564 and a second shaftportion 566. As depicted in FIG. 10, axes of first and second shaftportions 564 and 566 are aligned with one another. However, as depictedin FIG. 10A, axes of first and second shaft portions 564 and 566 can beacutely oriented with respect to one another.

The flange portion 550 can be other shapes and have other thicknesses.As depicted in FIG. 11, for example, intermediate portion 515A includesa post 552A similar to post 552 depicted in FIG. 10, but also includes aflange portion 550A that has a cylindrical shape with apertures 542A(for receiving fasteners 530) formed therethrough. Flange portion 550Aincludes a constant thickness between first surface 556A and secondsurface 558A. Furthermore, as depicted in FIG. 12, for example,intermediate portion 5158 includes a post 552B similar to post 552depicted in FIG. 10, but also includes flange portion 550B that has atri-lobed shape with apertures 542B (for receiving fasteners 530) formedtherethrough. Flange portion 550B includes a constant thickness betweenfirst surface 556B and second surface 558B.

As depicted in FIGS. 11 and 12, transitional portions 568A and 568B canbe respectively positioned between first and second shaft portions 564Aand 565A and first and second shaft portions 564A and 564B. Atransitional portion (not shown) can also be positioned between firstand second shaft portions 564 and 566 depicted in FIGS. 10 and 10A.

The first shaft portion 564 can serve in facilitating engagement with anaperture 570 formed in humerus H, and second shaft portion 566 can servein facilitating engagement with an aperture 572 formed in head portion512. In essence, second shaft portion 566 of post 552 serves as a malecomponent for receipt in a female component afforded by aperture 572 forjoining head portion 512 and intermediate portion 515. Like first andsecond shaft portions 406 and 408 of post 404, first and second shaftportions of 564 and 566 of post 552 can be configured to havecylindrical or frusto-conical shaped portions, and have regularroughened surfaces, irregular roughened surfaces, and/or smoothenedsurfaces provided on the cylindrical or frusto-conical shaped portionsfor engaging corresponding surfaces provided in apertures 570 and 572.

As depicted in FIG. 10, the connection between head portion 512 andintermediate portion 515 afforded by the interaction between thesurfaces of post 552 and aperture 572 serves in maintaining thepositions of head portion 512 and intermediate portion 515 relative tohumerus H. Indeed, portions of humerus H are clamped between headportion 512 and intermediate portion 515. Furthermore, the configurationof post 552 can serve in resisting movement (and hence, maintaining theposition) of the components of humeral head replacement system 510relative to humerus H. For example, if first shaft portion 564 includesthreads/ratchets (not shown), the threads/ratchets would resist linearrearward movement (or backing out) of post 552 from aperture 570, and,in doing so, serve in fixing post 552 relative to humerus H.

As depicted in FIG. 10, head portion 512 is substantially shaped as asubstantially solid spherical cap. Head portion 512 includes anarticular surface 576 and a bone-contacting surface 578. Articularsurface 576 is substantially similar to the shape of the articularsurface (or portions thereof) of the humeral head for which it is usedin replacing. Head portion 512, however, is not limited to the featuresdepicted in FIG. 10. Where compatible, head portion 512 could insteadinclude the features of the other head portions described herein.Furthermore, bone-contacting surface 578 contacts humerus H alongsurface S₁₃, and aperture 572 (for receiving second shaft portion 566)extends through bone-contacting surface 578 into head portion 512. Asdepicted in FIG. 10, bone-contacting surface 578 is substantially flat.However, bone-contacting surface 578 can be concave, convex, orundulating with various concavities and convexities to accommodate theshape of surface S₁₃. Surface S₁₃ can be prepared to interface with theshape of bone-contacting surface 578.

Depending on whether second shaft portion 566 of post 552 has regularroughed surfaces, irregular roughened surfaces, and/or smoothenedsurfaces, engagement of post 552 to head portion 512 would be different.Aperture 572 formed in head portion 512 would be configured toaccommodate the regular roughened surfaces, irregular roughenedsurfaces, and/or smoothened surfaces formed on second shaft portion 566.For example, if second shaft portion 566 includes threads/ratchets (notshown), second shaft portion 566 can engage (via complimentarystructures formed in and/or via interference, press, and/or frictionfits with) aperture 572. Furthermore, if second shaft portion 566 has asmoothened surface 580, second shaft portion 566 can engage (viainterference, press, and/or friction fits) a smoothened surface 582formed in aperture 572. The interactions afforded by the complimentarystructures and interference, press, and/or friction fits serve inattaching post 552 to head portion 512 by resisting linear movement (orbacking out) of post 552 from head portion 512 after insertion intoaperture 572.

Multiple posts 552 can be formed on intermediate portion 515 forengaging multiple apertures 572 formed in head portion 512. For example,in similar fashion to apertures 52 (and corresponding fasteners 50) offirst humeral head replacement system 20, the number, arrangement, andspacing of multiple posts 552 and multiple apertures 572 can vary. Likewith apertures 52 (and corresponding fasteners 50) of first humeral headreplacement system 20, these variations (such as the positioning thereofon either side of the longitudinal axis and pattern formed thereby) formultiple posts 552 can occur because second portion 518 is sized tocontact varying portions of humerus H. These variations can also occurbecause the desire to have multiple posts 552 obliquely oriented withrespect to head portion 512—multiple posts 552 would likely be parallelor close to parallel to one another to afford engagement with headportion 512.

In addition, rather than providing second shaft portion 566 of post 552as the male component, and providing aperture 572 in head portion 512 asthe female component for joining head portion 512 and intermediateportion 515, the male and female components could be provided ondifferent components. For example, as depicted in FIG. 13, a projection586 could be provided on a modified head portion 512M, and an aperture588 could be provided in a modified post 552M of a modified intermediateportion 515M. Projection 586 serves as a male component for receipt in afemale component afforded by aperture 588 for joining head portion 512Mand intermediate portion 515M. Projection 586 and aperture 588 couldinclude corresponding regular roughened surfaces, irregular roughenedsurfaces, and/or smoothened surfaces to facilitate a connectiontherebetween. Furthermore, like multiple posts 552 and multipleapertures 572 discussed above, multiple projections 586 and multipleapertures 588 can be provided in a similar fashion.

The tenth humeral head replacement system 600 is depicted in FIG. 14 inposition with respect to humerus H. Humeral head replacement system 600includes a head or prosthetic portion 602, a bone plate portion 604, anda base plate portion 605. Head portion 602 and base plate portion 605are also depicted in FIG. 15. Like head portion 22, head portion 602serves as a prosthesis for replacement of humeral head or portionsthereof, and, like bone plate portion 24, bone plate portion 604 isattached to humerus H to provide a rigid structure for attaching baseplate portion 605 thereto. Base plate portion 605 can be provided tocontact humerus H and attached to bone plate portion 604 to provide arigid structure for attaching head portion 602 thereto. The rigidstructure provided by bone plate portion 604 and base plate portion 605allows head portion 602 to be secured in position on humerus H.

As depicted in FIG. 14, bone plate portion 604 is attached to humerus H,and includes a first portion 606 and a second portion 608. First portion606 is used in attaching bone plate portion 604 to humerus H at oradjacent surgical neck SN, and second portion 608 is used in attachingbone plate portion 604 to at least one of greater or lesser tubercles T.Bone plate portion 604 includes a length and a longitudinal axisextending between a first end 610 and a second end 612. Furthermore,like the width of bone plate portion 24, the width (i.e., the dimensionsperpendicular to the length) of bone plate portion 604 can vary alongthe length thereof to facilitate contact with different portions ofhumerus H. For example, second portion 608 can be wider than firstportion 606 to accommodate contact thereof with both of greater andlesser tubercles T. An illustrative shape for the perimeter of boneplate portion 604 can be seen in FIG. 7.

Like bone plate portion 24, bone plate portion 604 includes both anupper surface 614 and a lower surface 616 extending along first andsecond portions 606 and 608. Like lower surface 36 of first and secondportions 26 and 28, lower surface 616 of first and second portions 606and 608 can be contoured to contact different portions of humerus H.

Furthermore, although not depicted in FIG. 14, first portion 606 caninclude apertures (similar to apertures 42) extending between upper andlower surfaces 614 and 616 that are configured for receiving fastenerssuch as bone screws 40. Like first portion 26 of bone plate portion 24,first portion 606 of bone plate portion 604 can be attached at oradjacent surgical neck SN using bone screws 40. Bone screws 40 canengage the apertures formed in first portion 606, as well as apertures(not shown) formed in humerus H.

Second portion 608 of bone plate portion 604 is configured to receiveone or more fasteners 620 therethrough. Fasteners 620 are used tofacilitate attachment of base plate portion 605 and bone plate portion604 to one another. In addition, fasteners 620 can engage humerus H, andcan also be used to secure humerus H between bone plate portion 604 andbase plate portion 605. To those ends, second portion 608 can includeone or more apertures 622 therethrough (extending between upper andlower surfaces 614 and 616) for receiving fasteners 620.

Fasteners 620 can each include a shaft 624 and a head 626. Shafts 624can serve in facilitating engagement with base plate portion 605 andhumerus H, and heads 626 can serve in facilitating engagement withapertures 622 of second portion 608. When lower surface 616 (at secondportion 608) is properly positioned with respect to humerus H, fasteners620 can be inserted into apertures 622, into apertures 630 formed inhumerus H, and into apertures 632 formed in base plate portion 605.Furthermore, apertures 622 can be countersunk to receive heads 626, sothat at least portions of heads 626 ultimately can lie below uppersurface 614.

Three fasteners 620 and three apertures 622 are depicted in FIG. 14arranged to have a generally parallel orientation with respect to oneanother. Fasteners 620 and apertures 622 are spaced along thelongitudinal axis of bone plate portion 604. Furthermore, in similarfashion to apertures 52 (and corresponding fasteners 50) of firsthumeral head replacement system 20, the number, arrangement, spacing,and orientation of apertures 622 (and hence, corresponding fasteners620) can vary further. Like with first humeral head replacement system20, these variations (such as the positioning thereof on either side ofthe longitudinal axis and pattern formed thereby) for apertures 622 (andcorresponding fasteners 620) can occur because second portion 608 issized to contact varying portions of humerus H, and the desire to havethe fasteners 620 parallelly or acutely oriented with respect to oneanother.

Like shafts 54 and heads 56, shafts 624 and heads 626 can be configuredto have cylindrical or frusto-conical shaped portions, and have regularroughened surfaces, irregular roughened surfaces, and/or smoothenedsurfaces provided on the cylindrical or frusto-conical shaped portions.Furthermore, apertures 622 can include corresponding surfaces tofacilitate engagement with heads 626, and apertures 630 and 632 caninclude corresponding surfaces to facilitate engagement with shafts 624.As such, fasteners 620 can interact with apertures 622, 630, and 632 toattach bone plate portion 604, base plate portion 605, and humerus Htogether.

Base plate portion 605 includes a flange (or plate) portion 640 and apost 642 extending outwardly from flange portion 640. As depicted inFIG. 15, flange portion 640 is cylindrical, and includes a first surface646, second surface 648, and an edge surface 650 extending between firstsurface 646 and second surface 648. Apertures 632 are formed throughfirst surface 646 and extend into flange portion 640. Furthermore, asdepicted in FIG. 14, first surface 646 contacts a surface S₁₄ of humerusH. Surface S₁₄ can be prepared to interface with the shape of flangeportion 640, and vice versa.

The number, arrangement, spacing, and orientation of apertures 632 cancorrespond to the same of apertures 622 formed in bone plate portion604. Given that flange portion 640 is cylindrical, the thickness offlange portion 640 between first and second surfaces 646 and 648 isconstant. However, flange portion 640 can have different shapes andthicknesses. For example, if flange portion 640 is frusto-conical, thethickness would increase from edge surface 650 toward the center offlange portion 640.

Post 642 can be integrally formed with flange portion 640. As depictedin FIGS. 14 and 15, the axes of flange portion 640 and post 642 arealigned with one another. However, as depicted in FIG. 16, post 642A canbe positioned on flange portion 640 such that the axes of flange portion640 and post 642 are offset from one another, and, as depicted in FIG.17, axes of post 642B and flange portion 640 can be acutely orientedwith respect to one another.

Post 642 can serve in facilitating engagement with an aperture 652formed in head portion 602. In essence, post 642 serves as a malecomponent for receipt in a female component afforded by aperture 652 forjoining head portion 602 and base plate portion 605.

Post 642 can be configured to have cylindrical or frusto-conical shapedportions, and have regular roughened surfaces, irregular roughenedsurfaces, and/or smoothened surfaces provided on the cylindrical orfrusto-conical shaped portions for engaging corresponding surfacesprovided in apertures 652. The connection between head portion 602 andbase plate portion 605, as depicted in FIG. 14, is afforded by theinteraction between the surfaces of post 642 and aperture 652. Asdiscussed below, the interaction serves in maintaining the positions ofhead portion 602 and base plate portion 605 relative to humerus H.

As depicted in FIGS. 14 and 15, head portion 602 is generally shaped asa substantially solid spherical cap. Head portion 602 includes anarticular surface 654 and a flange-contacting surface 656. Articularsurface 654 is substantially similar to the shape of articular surface(or portions thereof) of the humeral head for which it is used inreplacing. Head portion 602, however, is not limited to the featuresdepicted in FIGS. 14 and 15. Where compatible, head portion 602 couldinstead include the features of the other head portions describedherein. Furthermore, flange-contacting surface 656 contacts flangeportion 640 along second surface 648, and aperture 652 (for receivingpost 642) extends through flange-contacting surface 656 into headportion 602. As depicted in FIG. 14, flange-contacting surface 656 issubstantially flat. However, flange-contacting surface 656 can be shapedto correspond to second surface 648.

Depending on whether post 642 and corresponding aperture 652 haveregular roughed surfaces, irregular roughened surfaces, and/orsmoothened surfaces, engagement of post 642 to head portion 602 would bedifferent. Aperture 652 formed in head portion 602 would be configuredto accommodate the regular roughened surfaces, irregular roughenedsurfaces, and/or smoothened surfaces formed on post 642. For example, ifpost 642 includes threads/ratchets (not shown), post 642 can engage (viacomplimentary structures formed in and/or via interference, press,and/or friction fits with) aperture 652. Furthermore, if post 642 has asmoothened surface 660, post 642 can engage (via interference, press,and/or friction fits) a smoothened surface 662 formed in aperture 652.The interactions afforded by the complimentary structures andinterference, press, and/or friction fits serve in attaching post 642 tohead portion 602 by resisting linear movement (or backing out) of post642 from head portion 602 after insertion into aperture 652.

Multiple posts 642 can be formed on base plate portion 605 for engagingmultiple apertures 652 formed in head portion 602. For example, insimilar fashion to apertures 52 (and corresponding fasteners 50) offirst humeral head replacement system 20, the number, arrangement, andspacing of multiple posts 642 and multiple apertures 652 can vary. Likewith apertures 52 (and corresponding fasteners 50) of first humeral headreplacement system 20, these variations (such as the positioning thereofon either side of the longitudinal axis and pattern formed thereby) formultiple posts 642 can occur because second portion 608 is sized tocontact varying portions of humerus H. These variations can also occurbecause of the desire to have multiple posts 642 obliquely oriented withrespect to head portion 602—multiple posts 642 would likely be parallelor close to parallel to one another to afford engagement with headportion 602.

In addition, rather than providing post 642 as the male component, andproviding aperture 652 in head portion 602 as the female component forjoining head portion 602 and base plate portion 605, the male and femalecomponents could be provided on different components. For example, asdepicted in FIG. 18, a post 666 could be provided on a modified headportion 602M, and an aperture 668 could be provided in a modified baseplate portion 605M. Post 666 serves as a male component for receipt in afemale component afforded by aperture 668 for joining head portion 602Mand base plate portion 605M. Post 666 and aperture 668 could includecorresponding regular roughened surfaces, irregular roughened surfaces,and/or smoothened surfaces to facilitate a connection therebetween.Furthermore, like multiple posts 642 and multiple apertures 652discussed above, multiple posts 666 and multiple apertures 668 can beprovided in a similar fashion.

Additionally, rather than providing post 642 and aperture 652combination or post 666 and aperture 668 combination, head portion 602Dand base plate portion 605D, as depicted in FIG. 21, could includedovetail structures 670 formed thereon. Base plate portion 605D is alsodepicted in FIG. 20. Dovetail structures 670 provide for the connectionof head portion 602D and base plate portion 605D to one another.

Distal radius replacement system 700 is depicted in FIGS. 21 and 22 inposition with respect to a radius R. Distal radius replacement system700 includes a prosthetic portion 702 and a bone plate portion 704.Prosthetic portion 702 serves as a prosthesis for replacement of atleast a portion of a distal radius. For example, as depicted in FIG. 22,prosthetic portion 702 includes an articular surface 706 which serves inreplacing a portion of the carpal articular surface of radius R.Articular surface 706 can facilitate engagement with portions of a wristincluding a lunate and a scaphoid.

As depicted in FIG. 22, articular surface 706 is provided between dorsalrim DR and the volar rim VR of the carpal articular surface. However,articular surface 706 also could be used in replacing portions of thedorsal rim DR and the volar rim VR. Furthermore, bone plate portion 704is attached to radius R to provide a rigid structure for attachingprosthetic portion 702 thereto. The rigid structure provided by theattachment of bone plate portion 704 to radius R allows prostheticportion 702 to be secured in position on radius R.

As depicted in FIG. 22, bone plate portion 704 is attached to radius R,and, as depicted in FIGS. 21 and 22, bone plate portion 704 includes afirst portion 710 and a second portion 712. First portion 710 is used inattaching bone plate portion 704 above the distal end of radius R, andsecond portion 712 is used in attaching bone plate portion 704 at oradjacent the distal end of radius R. Bone plate portion 704 includes alength and a longitudinal axis extending between a first end 714 and asecond end 716. Furthermore, the width (i.e., the dimensionsperpendicular to the length) of bone plate portion 704 can vary alongthe length thereof to facilitate contact with different portions ofradius R. For example, as depicted in FIG. 21, second portion 712 iswider than first portion 710 to accommodate contact with the widerportion of radius R at or adjacent the end thereof.

Bone plate portion 704 includes an upper surface 720 and a lower surface722. Lower surface 722 can be contoured to contact different portions ofradius R, and first and second portions 710 and 712 can includeapertures 724 and 726, respectively, extending between upper and lowersurfaces 720 and 722. First portion 710 of bone plate portion 704 can beattached to radius R using fasteners such as bone screws 40 insertedthrough apertures 724 and into radius R. Bone screws 40 can engageapertures 724 formed in first portion 710, as well as apertures (notshown) formed in radius R.

Apertures 726 are configured for receiving fasteners 730 (FIG. 22) forattaching prosthetic portion 702, bone plate portion 704, and radius Rto one another. While four apertures 726 are depicted in FIG. 21, thenumber, arrangement, spacing, and orientation of the apertures 726 canvary according to the desired number, arrangement, spacing, andorientation of the fasteners 730.

Fasteners 730 each include a shaft 732 and a head 734. Shafts 732 canserve in facilitating engagement with prosthetic portion 702 and radiusR, and heads 734 can serve in facilitating engagement with secondportion 712. When lower surface 722 (at second portion 712) is properlypositioned with respect to radius R, fasteners 730 can be inserted intoapertures 726, into apertures 736 formed in radius R, and into apertures738 formed in prosthetic portion 702. Furthermore, apertures 726 can becountersunk to receive heads 734, so that at least portions of heads 734ultimately can lie below upper surface 720.

Like those of fasteners 50, 100, 160, 220, and 280, for example, shafts732 and heads 734 can be configured to have cylindrical orfrusto-conical shaped portions, and have regular roughened surfaces,irregular roughened surfaces, and/or smoothened surfaces provided on thecylindrical or frusto-conical shaped portions. The regular roughenedsurfaces, irregular roughened surfaces, and/or smoothened surfaces caninterface with corresponding surfaces provided in apertures 726, 736,and 738 to afford a connection between prosthetic portion 702, boneplate portion 704, and radius R.

Prosthetic portion 702 includes an articular plate-like portion 740 onwhich articular surface 706 and a bone-contacting surface 742 isprovided, and includes two fastener-receiving protuberances 744extending outwardly from bone-contacting surface 742. Bone-contactingsurface 742 can be prepared to contact surface S₁₅. Furthermore, radiusR at surface S₁₅ can be prepared to engage bone-contacting surface 742,and to accommodate fastener-receiving protuberances 744 therein. Onceprosthetic portion 702 and bone plate portion 704 are properlypositioned with respect to radius R, fasteners 730 can be used to attachprosthetic portion 702 and bone plate portion 704 to one another, and toradius R.

Fastener-receiving protuberances 744 include apertures 738 for receivingfasteners 730. While two apertures 738 are formed on each offastener-receiving protuberances 744, the number, arrangement, spacing,and orientation of apertures 738 can vary according to the desirednumber, arrangement, spacing, and orientation of fasteners 730.

Distal ulna replacement system 800 is depicted in FIG. 23 in positionwith respect to an ulna U. Distal ulna replacement system 800 includes aprosthetic portion 802 and a bone plate portion 804. Prosthetic portion802 serves as a prosthesis for replacement of at least a portion of adistal ulna. For example, as depicted in FIG. 23, prosthetic portion 802includes an articular surface 806 which serves in replacing thearticular surface of the head of ulna U. Articular surface 806 canfacilitate engagement with portions of the distal radius and portions ofa wrist including a lunate.

As depicted in FIG. 23, bone plate portion 804 is attached to ulna Uadjacent a styloid process SP to provide a rigid structure for attachingprosthetic portion 802 thereto. The rigid structure provided by theattachment of bone plate portion 802 to ulna U allows prosthetic portion802 to be secured in position on ulna U.

Bone plate portion 802, as depicted in FIG. 23, includes a first portion810 and a second portion 812. First portion 810 is used in attachingbone plate portion 804 above the distal end of ulna U, and secondportion 812 is used in attaching bone plate portion 804 at or adjacentthe distal end of ulna U. Bone plate portion 804 includes a length and alongitudinal axis extending between a first end 814 and a second end816. Furthermore, the width (i.e., the dimensions perpendicular to thelength) of bone plate portion 804 can vary along the length thereof tofacilitate contact with different portions of ulna U. For example, asdepicted in FIG. 23, second portion 812 is slightly wider than firstportion 810.

Bone plate portion 804 includes an upper surface 820 and a lower surface822. Lower surface 822 can be contoured to contact different portions ofulna U, and first and second portions 810 and 812 can include apertures824 and 826, respectively, extending between upper and lower surfaces820 and 822. First portion 810 of bone plate portion 804 can be attachedto ulna U using fasteners such as bone screws 40 inserted throughapertures 824 and into ulna U. Bone screws 40 can engage apertures 824formed in first portion 810, as will as apertures (not shown) formed inulna U.

Apertures 826 are configured for receiving fasteners 830 for attachingprosthetic portion 802, bone plate portion 804, and ulna U to oneanother. While two apertures 826 are depicted in FIG. 23, the number,arrangement, spacing, and orientation of apertures 826 can varyaccording to the desired number, arrangement, spacing, and orientationof fasteners 830.

Fasteners 830 each include a shaft 832 and a head 834. Shafts 832 canserve in facilitating engagement with prosthetic portion 802 and ulna U,and heads 834 can service in facilitating engagement with second portion812. When lower surface 822 (at second portion 812) is properlypositioned with respect to ulna U, fasteners 830 can be inserted intoapertures 826, into apertures (not shown) formed in ulna U, and intoapertures 838 formed in prosthetic portion 802. Furthermore, apertures826 can be countersunk to receive heads 834, so that at least portionsof heads 834 ultimately can lie below upper surface 820.

Like those of fasteners 50, 100, 160, 220, and 280, for example, shafts832 and heads 834 can be configured to have cylindrical orfrusto-conical shaped portions, and have regular roughened surfaces,irregular roughened surfaces, and/or smoothened surfaces provided on thecylindrical or frusto-conical shaped portions. The regular roughenedsurfaces, irregular roughened surfaces, and/or smoothened surfaces caninterface with corresponding surfaces provided in apertures 826 and 838,and apertures formed in ulna U to afford a connection between prostheticportion 802, bone plate portion 804, and ulna U.

Prosthetic portion 802, as depicted in FIG. 23, is substantially hollow,and includes (in addition to articular surface 806) an interior surface840, a bone-contacting rim 842, an interior cavity 844, and columns 846.Interior cavity 844 is delineated at least in part by interior surface840 and bone-contacting rim 842. Articular surface 806 is substantiallysimilar to the shape of the articular surface of the head (or portionsthereof) of ulna U for which it is used in replacing. The thickness ofprosthetic portion 802 between articular and interior surfaces 806 and840 can vary, and bone-contacting rim 842 contacts a surface (not shown)of ulna U. The surface of ulna U can be prepared to interface with theshape of bone-contacting rim 842, and vice versa.

Columns 846 include apertures 838 formed therein for receiving fasteners830, and unfractured bone of ulna U, bone fragments of ulna U, and/or asubstrate (not shown) can fill interior cavity 844. While two columns846 are depicted in FIG. 23, the number, arrangement, spacing, andorientation of columns 846 (and corresponding apertures 838) can varyaccording to the desired number, arrangement, spacing, and orientationof fasteners 830.

In summary, systems 20, 80, 140, 200, 260, 340, 380, 440, 510, 600, 700,and 800 for replacement of comminuted bone portions and the method foruse thereof provide a prosthesis affording replacement of the comminutedbone fractures or portions thereof. Furthermore, while systems 20, 80,140, 200, 260, 340, 380, 440, 510, 600, 700, and 800 are used inassociation with the proximal end portion of the humerus, the distal endportion of the radius, or the distal end portion of the ulna, the systemand method of the present invention can be configured for use elsewherein the human body. Other embodiments of the invention will be apparentto those skilled in the art from consideration of the specification andpractice of the examples be considered as exemplary only.

I claim:
 1. A system for replacement of at least a portion of acomminuted humeral head, the system comprising: a prosthesis having anexterior surface and at least one aperture formed therein, said exteriorsurface being sized and shaped to approximate the surface of the atleast a portion of the comminuted humeral head; a first plate includinga first surface and an opposite second surface, said first surfaceadapted to contact an exterior portion of a humerus; a second plateincluding a first surface and an opposite second surface, said firstsurface including at least one post extending outwardly therefrom, andsaid second surface being adapted to contact an interior portion of thehumerus; and at least one fastener adapted to attach said first andsecond plates to one another and the humerus, wherein, when the systemis position with respect to the humerus, said first plate and saidsecond plate are attached to one another and the humerus with said atleast one fastener, and said at least one post extends through thehumerus and engages said at least one aperture formed in said prosthesisto connect said prosthesis and said second plate to one another.
 2. Thesystem of claim 1, wherein said first surface of said first plate andsaid second surface of said second plate are adapted to clamp a portionof the humerus therebetween.
 3. The system of claim 1, wherein saidprosthesis and said first surface of said second plate are adapted toclamp a portion of the humerus therebetween.
 4. A system for replacementof at least a portion of a comminuted humeral head, the systemcomprising: a prosthesis having an exterior surface and at least oneaperture formed therein, said exterior surface being sized and shaped toapproximate the surface of the at least a portion of the comminutedhumeral head; a first plate including a first surface and an oppositesecond surface, said first surface adapted to contact an exteriorportion of a humerus; a second plate including a first surface and anopposite second surface, said first surface including at least one postextending outwardly therefrom, said second surface being adapted todirectly contact an interior portion of the humerus, said first surfaceof said first plate and said second surface of said second plate beingadapted to clamp a portion of the humerus therebetween, and saidprosthesis and said first surface of said second plate being adapted toclamp a portion of the humerus therebetween; and at least one fasteneradapted to attach said first and second plates to one another and thehumerus, wherein, when the system is position with respect to thehumerus, said first plate and said second plate are attached to oneanother and the humerus with said at least one fastener, and said atleast one post extends through the humerus and engages said at least oneaperture formed in said prosthesis to connect said prosthesis and saidsecond plate to one another.
 5. The system of claim 4, wherein saidsecond plate includes a central longitudinal axis extending through saidsecond plate and said at least one post, said second plate having afirst maximum cross-sectional dimension perpendicular to the centrallongitudinal axis, and said at least one post having a second maximumcross-sectional dimension perpendicular to the central longitudinalaxis, the second maximum cross-sectional dimension being less than halfof the first maximum cross-sectional dimension.
 6. The system of claim4, wherein said first surface of said second plate is substantiallyoriented in a first direction and said second surface of said secondplate is substantially oriented in a second direction, the first andsecond directions being opposite to one another.
 7. The system of claim4, wherein said at least one post includes a first end and a second end,said at least one post being attached to the remainder of said secondplate at said first end, and said at least one post tapers from saidfirst end toward said second end.
 8. The system of claim 7, wherein saidsecond plate includes a central longitudinal axis extending through saidsecond plate and said at least one post, said second plate having amaximum cross-sectional dimension perpendicular to said centrallongitudinal axis, said first surface of said second plate taperingtoward said at least one post from adjacent the first maximumcross-sectional dimension.
 9. A system for replacement of at least aportion of a comminuted humeral head, the system comprising: aprosthesis having an exterior surface and at least one aperture formedtherein, said exterior surface being sized and shaped to approximate thesurface of the at least a portion of the comminuted humeral head; afirst plate including a first surface and an opposite second surface,said first surface adapted to contact an exterior portion of a humerus;a second plate including a first surface and an opposite second surface,said first surface of said second plate being substantially oriented ina first direction, said second surface of said second plate beingsubstantially oriented in a second direction, the first and seconddirections being opposite to one another, said first surface includingat least one post extending outwardly therefrom, said second surfacebeing adapted to directly contact an interior portion of the humerus,said second plate including a central longitudinal axis extendingthrough said second plate and said at least one post, said second platehaving a first maximum cross-sectional dimension perpendicular to thecentral longitudinal axis, and said at least one post having a secondmaximum cross-sectional dimension perpendicular to the centrallongitudinal axis, the second maximum cross-sectional dimension beingless than half of the first maximum cross-sectional dimension; and atleast one fastener adapted to attach said first and second plates to oneanother and the humerus, wherein, when the system is position withrespect to the humerus, said first plate and said second plate areattached to one another and the humerus with said at least one fastener,and said at least one post extends through the humerus and engages saidat least one aperture formed in said prosthesis to connect saidprosthesis and said second plate to one another.